This stuff is supposed to be very resilient, and it's supposed to cure under adverse conditions.
RV Roof Repair with Liquid Roof and Liquid Rubber
I can tell you from experience that it is very good at stopping leaks. I've never used it under freezing conditions, but I have used it where it got wet just hours after application and it was just fine. The manufacturer claims that it won't freeze, I have my doubts. My only complaint is that a gallon doesn't cover a very large area.
The stuff RanCarr is talking about is probably called Kool-Seal and is designed mainly for mobile home roofs.