Hello, Neighbor. I live in Fargo and have smoked in -20F with zero issues other than not liking to go outside to get the smoker ready and pull the meat out when it is so dang cold.
The only issue that you may have, is that your thermometers will not register until they hit 30 or so. So you may have to dip them in a glass of hot water or use a hair dryer or some other means of heating up the probes.
Do you have a D model or an analog? If an analog, it will eventually come up to temp on its own without heating the probe. If you have a D model with the built-in Auber probe I am not sure if heating the probe is necessary or not (I have an analog #3).
But, once you get going, it may take an extra 10-20 minutes to get to temp, but once you are there it will not have a problem maintaining temp in very cold weather.
hopefully this helps.