1. It can be done. Fish shipped from their collection sites can sometimes go 36+ hours in a plastic bag, although they are pumped full of oxygen.
2. Starting 3 or 4 days before the move, don't feed anything! It's better for them to be a little hungry when you get there than to poop in the container and pollute the water, causing a fatal ammonia increase.
3. Any chance of being able to drive through the night and making it a one-day trip? Anyone else in the car who can drive shifts with you? Back when my family used to go on holidays, my father would drive straight through from Canada to Key West, all 35 hours of it, with my mother only taking a two hour turn in the middle so he could take his eyes off the road. With enough caffeine in your system, anything can be done.
