when we were FL residents and going every wknd, instead of buying every meal, every day: we'd take sandwiches (grilled cheese was a fav since processed cheese no meat lasts longer in high heat or at least I think) in a foldable lunch bag w/ a frozen water bottle that could be drunk after we eat). apples occasionally. In back pack, always a refill water bottle (sometimes brittle filtered) nuts (high calories), chip/cracker types (Stacy's pita chips can't really get crunched up and heavy/highly filling). The single jerky vacuum sealed is fine, but beware that the big bags will get moldy in the high humidity if you don't eat that day. Sometimes take a banana (try to be careful not to smash), for the potassium, to offset the dehydration. We always take our breakfast to avoid the extra time for the meal and $ (typically rice crispy treats early before it melts or the kind). Trail mix, combos, pretzels, dried fruit. Your Disney resort will have pb/jam packets for sandwiches (toaster, mic) if you just brought bread and zip bags (I don't do this). Just be mindful of things that melt like choc.