We have made our last 2 moves with 3 cats, one in-state and one out of state. We just put the cats in their carriers, and they did fine. We just made sure if we had to stop for restroom, etc., that we had someone stay with them to keep the air running. I think we managed to avoid stopping for any meals, just because this wasn't an especially long move for an out-of-state one. When we arrived, we immediately set up their food and litter box in a bathroom and isolated them there until furniture was in.

We made our longest out of state move when we had just one cat. (Louisiana to Georgia) We also didn't have kids at the time, and we were able to let her out of the carrier some. We had food and a litter box set up, and I don't think she used either the entire trip. We tried taking her out on a leash at a rest area, and she hated that. The cars and trucks frightened her.