A complicated topic.
Some reference resources which will be helpful; I highly suggest printing out the pages that have the most relevant info so you have it on hand in case it is needed.
Canadian Transportation Agency:
Accessible Transportation for Persons with Disabilities Regulations
Regulations https://otc-cta.gc.ca/eng/accessible-transportation-persons-disabilities-regulations
Travelling with Mobility Aids and other Assistive Devices : A Guide
https://otc-cta.gc.ca/eng/publication/travelling-mobility-aids-and-other-assistive-devices-a-guide
Severe allergies: A Guide
https://otc-cta.gc.ca/eng/publication/severe-allergies-a-guide
CATSA:
Medication and Medical Items
https://www.catsa-acsta.gc.ca/en/medication-and-medical-items
Special Needs:
https://www.catsa-acsta.gc.ca/en/special-needs
Key from the special needs CATSA page (I have added the bold):
"You can bring medical implants, mobility aids and assistive devices. They can be brought in addition to the two carry-on bag limit."
Carry-on or Checked:
https://www.catsa-acsta.gc.ca/en/carry-or-checked#carry-on
Air Canada carry-on baggage, see other special items / medication and medial/mobility devices:
https://www.aircanada.com/ca/en/aco/home/plan/baggage/carry-on.html
Per AC's policy at that page:
The following items are allowed at all times, in addition to your carry-on allowance:
- Mobility aids (e.g. braces, cane, crutches, walker, communication device*) or other special need items
- Tools of any size which are required by a passenger with special needs who is travelling with a mobility aid
- Battery-powered medical equipment (such as CPAP and sleep apnea devices) and Personal Oxygen Concentrators
- Medication in its original, labelled container
- Syringes or hypodermic needles for personal medical use (e.g. Epipen), provided the needle guards are intact, and that they are accompanied by the prescription medication with a printed label identifying the medication name and the issuing medical office or pharmacy.
- Container carrying life sustaining items
==
Now to the complicated...
The medications, especially in original containers, should be fine. For the non-Rx liquid medications, the issue will be not having what may be considered an excessive quantity in the absence of a physician's note or prescription. FWIW, I have carried a bottle of cough syrup and antihistamine and some additional liquids for a medical device and not had an issue.
The key for liquid medications that are NOT in your 3-1-1 bag is you need to declare them to the screening official up front before they go through the screening machine. What I do is say "I have liquid medications that exceed the 3-1-1 rule; do you want me to put them in the tray or leave them in my bag" and then follow their direction. I keep them together in a double ziploc that is quickly accessible so they are easy to grab and put into the bin. The double ziploc protects from leakage and protects the bottles from the dirty bins.
With medical liquids I am almost always selected to go through additional screening, which involved at least a couple of: pat down, searching my carry-ons, and swabbing and/or scanning the liquid bottles. If they are going to search my bag or handle the medications/bottles, I ask them if they could please wear new gloves when they do so - only once have I had push back on that request, but even then they did change their gloves.
The food would be likely to be a challenge if you wanted to include it as being exempt form your carry-on allowance. IF it was actual medical food or you have a physician's letter or prescription, then you could show medical necessity. Without that you may end up in an argument over whether the food counts as "other special needs items"; and if you lose the argument than you are in a pickle of what to do with the food.
I always put food in my carry-on when crossing the border. I find it much easier when dealing with border officials if there are questions to be able to pull it out and show them then to have it in a checked bag somewhere off in the bowels of the airport. I also have a written list of all the food I have (including things like gum and mints and candy, those are food too!) which I include with my customs declaration (all food must be declared).
I have traveled various ways many times - with extra medical bags (carry-on and checked) and without. Let me tell you about the point I have come to now and why, and perhaps it can help inform your decision-making.
When I travel by air, at a minimum I am carrying on a carry-on and a personal item. I am also checking probably two bags. A chunk of all of that is medical items. I have found that while it is nice to be able to have my core medical items in their own exempt carry-on and then use the carry-on and personal item for mostly non-medical items, to be honest, it is a real pain to be carrying around three (or four, have done that once, do not recommend) items through the airports, onto the plane, etc, plus doing them plus the checked bags.
So, I ensure I have good travel insurance that covers me for interruption and baggage issues (delay, loss).
For carrying on: a personal item (currently a Pacsafe backpack that meets the smallest combined dimensions between Air Canada and WestJet); in that goes tablet, purse, phone, chargers, 2 Epipens (I also carry 2 on me with emergency allergy meds, and others are in the carryon), 3-1-1 and liquid meds, important documents, and some other key things.
And a hardside carryon with 4 spinner wheels that meets the smallest combined dimensions between AC and WJ. First an foremost this holds all medications (Rx and non-Rx), as well as electronic medical devices. It also holds the medical supplies I absolutely must have at destination (or there will be medical consequences) and cannot reasonably locate there nor improvise an alternative to. If there is room left, some non-medical items go in that bag, e.g. pair of underwear, socks, and a top, so I could change clothes. And the allergy-safe food I am bringing (note: I don't bring as much as I used to as I have identified some brands in the US that are safe for me, and come up with some solutions; plus when we visit WDW or
DCL we don't need much of our own food, just a few snacks, plus food for the travel itself). If I have to for space reasons, three of the medical devices fit in a relatively small bag that I can carry on its own as a third item that would be only those medical devices.
The checked bags get all the normal stuff, clothes etc etc etc as well as the remaining medical supplies - the ones that I could replace at destination or improve an alternative for (though I would not be happy if they went on a little adventure without me!). If those bags go on an adventure, that is where the baggage insurance kicks in, as well as the airline compensation. Part of that plan means I have a list of EVERYTHING that goes in all the bags, which bag it was in etc. And I take pictures of the contents of the bags. And pictures of the bags themselves (so if one goes astray you can show the picture and go "it looks like this"). We also now have an Air Tag for each bag.
We tend to fly premium economy for the extra space, but the fare also includes two checked bags. And sometimes is not tha tmuch more than economy once you factor in that we would pay for roomer seats and checked bags anyway. But even if we wouldn't and went straight economy, the cost of a checked bag on AC is not too bad compared to some other airlines.
https://www.aircanada.com/ca/en/aco/home/plan/baggage/checked.html#/
Finally, with regard to finding safe foods. Some of what I did is to first see if the foods I use here are available in the US. So something like Enjoy Life brand, yes; Ripple, yes; and it is the same product in both Canada and the US. That kind of information can usually be determined from the manufacturer's website or by reaching out to the manufacturer. Alternatives takes some digging. However, it is so much easier now with online shopping !!
In the WDW area the goto stores I will look at to discover what options may be and availability are: Whole Foods, Publix (major grocery store), Target, Walmart, and
Amazon Fresh. Some other places that are helpful are the Snack Safely site (two of my allergies are peanut and tree nut, so their list of pn/tn free foods gives me a starting point for some foods to see if they may be safe for my other allergies) and the Go Dairy Free site (same idea, as I am also allergic to milk).
I am stricter on my food choices when traveling than I am at home. So for example if I get bread, I want a product that is explicitly "free from dairy, nuts (tree nuts and peanuts)", while in Canada I am satisfied with bread that does not contain my allergens by ingredient and the company labels for "may contain" (including they just added may contain milk for some of their products due to a new shared line for those products... sucked because I can no longer have the products, but I appreciate the voluntary transparency). In the US it means the only bread options I get so far are GF/DF even though I don't need the GF, as I haven't found a non-GF bread that meets my critera and is safe. In Canada there is one brand of wheat bread I go with and I have several options within that brand.
If you want some help ID'ing some food options/alternatives, drop me a PM and I'd be happy to help.
Hope this helps !
SW