Yea, your best bet is to keep calling every morning, although at this late date, you're going to need all the luck you can get! Thanksgiving is one of the busiest times of the year, especially in FW, it gets quite crowded.
Our family has a annual get together at Thanksgiving every year in Fort Wilderness, we'll be there this Thanksgiving from 11/20 till 11/27. Brothers, fiancees, mothers, dads, and kids, it's without a doubt the best trip of the year. Last year was just mild temperature wise, hopefully this year it will be cold again like it was 2 years ago!!! (Thanksgiving time 2 years ago in FW was BITING cold, in the low 40's at night).
If you can get the ressies, you'll absolutely love it, why it is crowded, you get great temperatures, and everyone is putting the Holiday lights up on their campsites!
We'll once again have the big lighted mickey mouse ears hanging from the trees, and who knows how many lights on the golf cart!!!