I'm not going until June but I already have a rough itinerary sketched out. I plan to stay on program the entire time (fingers crossed).
At most restaurants you can order a steak, burger, or some other protein with a salad and veggie so I'm not worried at all. I know we'll eat at a few buffets (Crystal Palace, Donald's and 1900 Park Fare - all for breakfast). Snacks will be sugar free treats in the parks, nuts brought from home, fruit from one of the stands or popcorn and a diet soda. Since we're staying at the Grand Floridian, I know Gaspirilla Grille is opening 24 hours a day and I know I can always find an acceptable snack, even if we are at the parks late.
We're trying RainForest Cafe for the first time and I've already been to their site and found a couple of dishes I am excited to try.
I hope staying on plan won't be that difficult, especially if you have made up your mind to go into the situation not willing to compromise. Some people suspend their diets while on vacation but I'd like to see if this truly is a "lifestyle" change for me. I also plan on working out each day at the gym at the GF.
Please report back and let us know how you did!