We're a family of 5, and avoiding restaurants is big, HUGE savings for us. There is a big wal mart not far from where you're staying; it and the publix are both good.
We tend to buy frozen stuff to re-heat in the oven. It's a compromise between saving $, not spending too much time cooking and eating healthy. If we were in a restaurant the kids would want chicken nuggets anyway. They don't complain because 1 parent takes the kids to the pool while the other has a relaxing break from the kids while the oven (and dishwasher) do most of the actual work.
Tacos, mini-pizzas, anything they can assemble themselves is usually a hit. Salad-in-a-bag kits are helpful and not much of a premium, still big savings compared to a restaurant. Frozen fruit-in-a-bag with ice cream or yogurt makes a nice desert that's 50% healthy and refreshing on hot pool days, little work (and the kids can assemble their own sundaes). Our unit had a blender and we made smoothies 2 or 3 times.
I bet the vistana has a BBQ you could use, but IMHO that eats up a lot of time... maybe if you wanted a big block of relaxing downtime.
Surprisingly, my kids didn't mind skipping treats in the parks, although we had a few. They recognized they could eat granola bars and drink from a water bottle while waiting in line, so they didn't waste time sitting at table or counter service when they could be riding!
We did go to Golden Corral one night. My wife is allergic to MSG, so the only thing she could eat was the roast turkey. We were told it was in the salad bar and didn't take chances, but they probably meant it was in the dressings. The kids loved to pick their own meal, it was another highlight of the trip for them. I can hardly stand GC myself, but put up with it since the kids enjoyed it so much.