If you plan on being at WDW from November 13 - 18, I think you'll see lots of Holiday decorations at all the Parks and resorts.
Last year, we were at WDW from November 10 - 20. Looking back at the date stamp on our photos (which are more reliable than my memory), all of the Parks had some Holiday decorations up by the 10th: DHS, Epcot, and Animal Kingdom Park had their trees up no later than 11/12. Also, Mickey and Minnie were wearing their Holiday costumes for meet & greets by that time.
The resorts were just starting to put up their decorations when we arrived on November 10. AKV did not put up their big trees until the night of the 15th, but some resorts, such as BLT/Contemporary had theirs up sooner than AKV. If I recall correctly, by Saturday (11/17) every resort we visited had their Holiday decorations on display.