Many tip sites will tell you to never go to Disney whenever kids have off from school, but those are the only times I can go! Being a teacher, I am tied to taking vacations at those busy times and have experienced many of them: Thanksgiving, spring break, MLK Weekend, July 4, summers, etc.
Although it's been a few years since I went to Disney on Thanksgiving (the first being my honeymoon!), I found it totally doable and enjoyable. The weather was beautiful, the decorations were delightful, and the crowds were manageable with a good plan. Compared to the summer and spring break, I did not notice a big difference in the crowd levels and MLK weekend seemed even busier to me!
That being said, I did not attempt to go to MK on Thanksgiving day and spent the day at other parks instead. I have eaten Thanksgiving dinner at 1900 Park Fare, Chef Mickey's, and Whispering Canyon Cafe, so even those experiences were outside the parks. My dream meal for Thanksgiving would be Liberty Tree Tavern of course, but I don't think that will ever happen!
We are actually considering a trip over Thanksgiving this year - just started mulling it over. Knowing that our planning is WAY BEHIND, does anyone have suggestions for a good meal for Thanksgiving and it might still be possible to snag an ADR this late?
OP, good luck with your decision!