We will also be taking our 2 dogs. We plan to start about halfway through and stay at a hotel. So I have Hartley who hates car rides, he howls the whole time, he also hates the dogs. He and Little Man are really close so I thought I might put them in a large carrier together and that might help keep him calm. Psy will be by herself. I was wondering if the calming collars and calming spray would help keep them all calm. Also how big do the carriers need to be. I know they should have a small litter pan, but should the food and water be available at all times or just offered periodically. Because it will be summer any advice on how to keep them hydrated would be great, just in case they're to stressed to drink much. I know this will be a pain but I can't leave my babies.