Thank you both for your advice. We kept the car running with the heat on while we loaded up the tank, and kept the snake in the house until we were ready to go - the whole transfer went off without a hitch, though he was certainly happy to get out of the pillowcase. *laughs*

Luckily, his previous caretaker had just cleaned the tank last week after he finished his last shed so it won't be any problem leaving it relatively untouched until he's acclimated. All told, he seems quite content.

Thanks again!