dang man... should always take care when driving out in the cold. Plastic gets "BRITTLE" I've never broke an RPM part yet but my buddy had issues trying to get a warranty part because it wasn't a fail of the part when he was jumping 30ft, fail of stupidity...lol
Not to sure if it will be the same for running in the cold then slamming into something. I believe the warranty will cover just about anything, might just want to give them a call and see what they can help you with.
Good luck with your issue