We are going the week after Thanksgiving, but I don't think there is a huge difference in crowd levels between the two weeks. Both have Christmas parties that will close MK @ 7 on 4 nights, but the week after thanksgiving, on the 30th, MK will close at 4:30 instead of 7 for a cast member party.
Maybe check dining reservations and see which week you have better luck with getting what you want??