We stay at the resort all day on Thanksgiving, we like to avoid the parks. We make it a pool day or just a resort day. This past Thanksgiving we did Cape May Cafe breakfast at 8:30, then had a YC/BC photo shoot at 10am. We spent the day wandering around in the arcades, shopping, boardwalk etc.. Then dinner at Yachtsmen's Steakhouse.
That's just us. We don't venture into the parks on Thanksgiving Day. They tend to reach capacity and have several closings throughout the day. I wouldn't chance an ADR in a park unless you plan to be there from Rope Drop.