I'm sorry, I should have been more clear. We wouldn't be blending up their food, we'd just bring HIS food. He has to have a certain number of calories but has volume restrictions, so usually just blending up regular meals won't get him the calories/mL that he needs.
Right now, when we travel, we've always driven, so I just throw his frozen blends into a cooler and toss them in the freezer at our destination (which we ensure in advance HAS a freezer). Then when we're out and about during the day, I pack his food in small pouches meant for baby food, toss them in a small cooler (lunchbag) with an ice pack, and we're good. But we're not usually out for an ENTIRE day. I'm not sure I can keep an entire day's worth of blends sufficiently cool, but maybe I can? But the big question is How Would I Get His Food To Florida?
Perhaps switching to the more expensive Real Food Blends would be easier, since I could ship them down in advance.
Commercial-packed foods (like Real Food Blends) usually get less scrutiny at security checkpoints than homemade blends, as well, but I don't know how much scrutiny to expect at the security stops at the parks.
I was just looking for first-hand experiences.