Make sure your animals are very well hydrated before the trip, AC tends to dry out the air. Also, don't feed them much the day before the trip and not at all the day you drive, so that food won't sour in their bellies if their body temps are on the low side.
Carry bottled water and some sphagnum moss in case the cool packs fail or the AC stops working so that you can keep your animals from overheating. It sounds like you've pretty much gotten your plans in order already! Good luck with the move.
The Zombie Mama is here!