I would definitely avoid leaving my bike in the car under those circumstances. If I did, I'd probably try to park the car by my room's window, and go check on it every half an hour. It would maul my buzz.

If I had to, I can see putting it under a blanket. How about asking them if you can put it in their basement?

B&B's are pure evil. I avoid them now at all costs, ever since I got held captive by a Christian couple at breakfast who were bent on explaining to the group how rock & roll, punk and metal were 'the devil's music.' I told them I would've gone insane without such music, which almost, almost shut them up.