No doubt in the world the cold weather is causing it. Just look where everyone lives who is complaining. And with the arctic front diving south this week, additional folks are having this problem. I have 3.5K miles on my truck (which I love btw) and got my alert yesterday when it was 15 degrees. I would bet money that this is a hardware issue and not a software issue. The cold is causing something to contract and a code is being thrown to the truck.
This should not be hard for GM to figure out with the team of folks they have. They also better get ahead of it before it blows up in their face. This forum has sounded the alarm and given GM time to fix this before others are affected or before others choose to buy something else. The vehicle industry is hurting right now, GM cannot afford to lose sales.