@dlowan,
Hey Bunny, poor Sebastian might get weirded out when you get to the new place. Kitty's take a little time to adjust. You might want to ask your Vet about a mild tranquilizer for the day you move and a few days to settle in. I don't like to dope up my pets, but I had a Springer Spaniel that was so freaked out when I had the siding replaced on the house, she refused to go near the discarded siding (the genius crew removed all of it and it was stacked in a pile on every side of the house) and would not relieve herself. My Chloe was a big scaredy-cat, and the vet gave her something so she could relax and finally step over the siding. The crew didn't pick that siding up for two weeks, the house was all tarpaper and plywood, a total eyesore. poor Chloe couldn't hold it for two weeks, and she was immaculate in the house....she would have sooner blown up than tinkle in the house.
I'm not going to recommend the tranks, they might be bad for cats...but check with your vet and see what they say.