We like to order pizza for dinner the night we check into our hotel. We always make sure to order enough to have left overs. We buy Ziplock Bags and bring the leftover pizza into the park with us the next day. The kids love it, its filling, and lasts throughout the day.
We always make sure to book a hotel with a free breakfast and mini fridge. We fill up in the morning at the hotel, making sure that the kids eat the eggs, pancakes, sausage, and etc. to keep them full. We buy food from the grocery store and pack lunch into the park. We love eating uncrustables, we freeze them and pack them frozen. This keeps our other food cold and they are perfectly soft (and still cold) by the time we are ready to eat. We also love bringing cheese sticks, to-go applesauce, goldfish and any other snacks that your family enjoys. We like to having dinner in the park, it is vacation and it's fun to be able to spurge sometimes.
Honestly we my family of 4 did it was: We ate Breakfast for free at the hotel with getaway vouchers, we ate lunch at DisneyLand. Rose Tavern and Smoke Jumpers Grill the second day. For Dinner we had packed stuffed for sandwiches and took in a ice chest. At the hotel we loaded everything in the little fridge. We would stay at the parks until we get kicked out pretty much. So we get back around 12:40 a.m. You don't want to be roaming the streets or pay for overprices pizza. Save the money and use it to buy yourselves extra souvenirs. I have two teens and they both agreed to be on a budget so we can splurge on shirts and stuff.