Hi Courtney,
What a wonderful way to spend Thanksgiving with your loved ones! I can't think of anywhere I'd rather spend one of my favorite holidays. I'll bet everyone is just so excited.
So the answer to this question really depends on how early you plan to start your day in the park(s). I would certainly recommend arriving as early as possible to insure you are ready and waiting as soon as the park opens. If I had to choose just one park, it would definitely be Magic Kingdom, HANDS DOWN! Since your children are older, you'll be able to see a lot in just one day and this is the park that really represents Disney magic to me, and is not to be missed.
I think you would have enough time to spend most of your day at Magic Kingdom and then head over to either Epcot or Disney's Hollywood Studios later in the afternoon and into the evening. It's absolutely possible to see two parks in one day and that's where a Park Hopper ticket really comes in handy! Hop on over to the
Walt Disney World Resort website to read about the offerings of each park to decide which ones you'll visit. Be sure to rest well prior to your visit, because you'll need to be prepared for a FULL day of magic and excitement!
Best Wishes,
Amanda F.