Before you even look at container size; need to map trip and check weather along the way. While vehicle is moving you can control with AC/Heater the environment inside vehicle; but once stopped (i.e. gas, food, etc.) that vehicle can cool down or heat up to dangerous levels for frogs in a matter of minutes. I've traveled for 9 hours with frogs by myself and stopping was the main concern.

You need to have back up plans in case of vehicle mechanical issues; specially if traveling in Summer or Winter. A large disposable foam ice box with ice packs and a plastic critter box could save your frogs in the event of an AC failure. Heat pacs could help too in case of heating issues.

Let your friends know you are traveling with frogs and will need a quiet place with electrical outlet for them. A trip that long will also need to secure frog's food sources, either packed for trip or bought along the way.

Depending on vehicle it's vital you can secure the enclosure to it. If a car; see if you can use the seat belts to prevent enclosure movement. It's very important not only for frogs; but for vehicle occupants. Last thing you want is to be have a large glass enclosure flying around in a vehicle should an accident happen. Hope this helps and good luck !