I use a Luggage Works cooler. I use Rubbermaid locking containers for food and ice.

Lock-its Food Storage Containers | Rubbermaid

They don't pop open in flight and have gaskets to keep liquid in. The large one I use for ice leaks a little but not much.

Ice is the only cooling medium that's renewable on the road because there's usually no way to refreeze any cold packs. Freezers are usually not available.

I freeze my four evening meals the night before leaving. I bring a bag of granola and fruit for breakfast. Usually blueberries in a smaller locking Rubbermaid container. I also bring a container of mixed cut fruit. Four to five Detour protein bars for lunch and sometimes RTD (ready to drink) protein drinks that don't need to stay cold.

The only thing I pay for are the small milk containers out of the wheel of death (.65) and coffee. If I have a good crew that wants to go out then I'll go out with them at least once and save the meal I brought with me.

Never give up crew moral to save a few bucks.... That's priceless.