I drive it down to 15 degree weather-ish. that is about as cold as it gets here in WA. I take it up to ski areas, but that is about as cold as I've ever seen it. Rarely goes below freezing in the city where I live, I just take it on trips to the mountains.
EGR blockoff and FIAV blockoff or bypass gives me a CEL, right? That doesn't bother me too much, eventually I will ESMlink the car. Maybe sooner than later, I would like to make sure the ECU is in good shape.