We first made our Thxgiving ADRs out at 180 days from arrival. But then it turned out at about 100 days out that some freinds were going to be meeting us there. We adjusted our ressies a little and upped the party size froim 4 to 7; in some cases we had to move the times around and we could not get anywhere near Le Cellier, which we had the day before. But now we have our ADRs all set, mostly.
You might have some luck if you are flexible on times and restaurants. I;d recommend that you call with a list in order of preference (times, restaurants...)
There are a number of very attractive special Thxgiving meals at WDW restaurants. We chose the Flying Fish for location (also staying at BWV) and menu and are really looking forward to it.
Good luck!