If you really plan to be gone in the parks open to close, then a big breakfast is worth cooking, get you ready for the day. Plus you have a fridge to freeze water for bringing into the parks; can prepare snacks to bring too (individually wrapped cheese, kept in a cooler with the frozen/cold waters works well) or brown bags as someone else posted, which saves $.
The trick is to not overbuy: if you are only doing breakfast, plus a late-night snack (i.e. save the ice cream bars for home rather than the park) then buy just that. If you know you will have at least one day that is just pool/shopping and not in a park, then buy food just for that day. Or order out as others have suggested. You can always buy more if needed, that way you will not be dumping a full fridge. FWIW.
The trick is to not overbuy: if you are only doing breakfast, plus a late-night snack (i.e. save the ice cream bars for home rather than the park) then buy just that. If you know you will have at least one day that is just pool/shopping and not in a park, then buy food just for that day. Or order out as others have suggested. You can always buy more if needed, that way you will not be dumping a full fridge. FWIW.

) and these meals are perfect to pack in a cooler for the 9 hour drive. I do like the take-out menus in the car for pick-up on the way home from the parks though- have to make a note of that.
We either decide what we'd like by viewing the website menu in advance or we print the To Go menu and bring it along to decide right before calling. This works awesome for our family as we generally aren't in the mood to go and sit in a restaurant for a long meal after spending the day in the parks. We do, however, leave the parks a bit early on our last night, go back to our townhome and change/clean up, then go for a nice dinner IN a restaurant on our last night. The kids seems to enjoy this tradition.

