After 4 days at -20C, I got the same symptoms including the limp mode. I brought the car straight to the dealer and they identified a throtle actuator faulty. They proposed to replace the throttle body at 900$ but I refused. I have another one at home I can install if needed.
Since I'm back from dealer, I have no issue and put the car in garage. I suspect a frozen throttle issue so no need to replace the part.
Any comments guy?