How long is your vacation?
When I was checking out Garden Grocer, their prices seemed to be in alignment with my grocery store, at least for the organic things I ususally buy. You can get a fair amouint of food for $54.00 (the $40 minimum plus $14 shipping).
Here is what we brought with us last trip:
Homemade cookies
2 boxes of cereal
2 boxes of Annie's Snack mix
2 boxes of granola bars
1 box of frozen Stonyfield Go-gurts. We had a direct flight which was only 3 hours. They started frozen and were half thawed when we unpacked.
Parmalait makes shelf stable milk you can buy by the quart. It only requires refrigeration once it's been opened. It's real dairy cow's milk, just ultrapasturized and packaged to not spoil.
I think during the flight the baggage is kept in an unheated hold, so it stays pretty cold. The concern is how long they leave your bags on the tarmac once you arrive in the heat of FL. I bet with a cooler with a cold pack I would feel comfortable to pack some hard boiled eggs for sandwiches and grab and go protein.
You can get very creative stretching restaurant take-out. If I were staying somewhere with a decent restaurant, I would get steak to go, and bring it in the room and make a meal out of it by cooking some broccoli with the boiling water and some instant rice with boiling water also. Most restaurant steaks can feed more than one person. I may also do this type of thing with a chicken parm. I learned from my uncle (he hikes the Appalacian trail) that pasta does not need water boiling the whole time to adequately cook, so maybe just put the pasta in hot water and change the water once to get it hot again. Then you can stretch the chicken parm too. Check and see if your hotel has a continental breakfast, if so, you might be able to use the toaster during the day, and you could make some toast, put some cheese in between while it is still hot, microwave some soup and have grilled cheese and soup.