The Liberty Tree Tavern at the Magic Kingdom is known for its traditional "Thanksgiving" dinner. I believe it's a character dinner, and if I were you, I'd book it right away because I'm sure the people going down to Disney at the time will have the same idea.
My family has spent many a Thanksgiving at Disney, and we love 1900 Park Fare. It has the traditional food, the characters, and it's at GF making very convenient but not nearly as crazy as LTT.