I've been saving the Arizona Ice Tea jugs, those are some thick polypropylene jugs! It will freeze, but won't burst if they are not filled more than 3/4 full. I'll stick one in my car and see how it does over the next few cold days we have.

My normal propel bottles are frozen in the morning, but usually thawed by noon, while parked in normal outside daylight. I would think this would be normal unless there is a total whiteout for days on end. (doubtful)