Back when I was a teen, we used to drive from Elizabeth, NJ to Naples, FL round-trip twice a year. Take these times with a grain of salt, because I think some of them are quicker now, but I haven't made this drive in years (decades).
(Pretty much all I-95 from NJ to FL.)
Elizabeth, NJ to the NJ/DE border -- about 2 hours (100 miles down the turnpike.)
DE - MD, about 15 - 20 minutes
MD - VA, about 2 hours, we took the eastern side of the beltway around DC. I've since driven the western side once, but the eastern side still seems quicker to me.
VA - NC, about 3 hours - this is before the 295 beltway around the Richmond - Petersburg area, so that may be a quicker route, but I have no experience here.
NC - SC, about 3 hours.
SC - GA, about 3 hours.
GA - FL, about 2 hours.
FL - Naples, about 6 3/4 hours. We used to get off I4 at state route 27, which is about 30 minutes past Disney. If I had to guess, I'd say 3 to 3 1/2 hours from the FL border to Disney, but that's just a guess.
From what I've read elsewhere, the trip can be made about an hour or so faster now then what I have above. The last two trips I made, I cut the driving at the DC area and took the Auto Train, so I have no recent experience with anything between the DC area and Sanford, FL.
Hope this helps.