leaving it in the cold isn't a problem..... the drastic change from really cold to really warm causes condensation.... that said....I have left mine in my car(up to 10 hours at a time)...I leave it in the trunk and then on my way home, I bring it up front with me, so it can gradually warm up a little.
I haven't had a problem yet.
( I won't leave it in the car in the heat though..... I have seen what my car can do to plastic!!!)