We have users in many cold locations and have not had any issues with our controller performing or being damaged. However, precautions should be taken to prevent water from entering the controller or blower then freezing. Additionally, even though it is very little, the controller generates heat, probably enough to keep itself functional if it is started at room temperature and put it in a container. Please note the LCD display on the controller is only rated to operate to -4 F.
If extreme weather conditions are expected or experienced during cooks, we have had users place a non-metallic bowl turned upside-down over the controller to protect it from water, sleet, snow and freezing rain. Users have also fashioned an aluminum foil "tent" over and around the blower to prevent extreme wind and rain from infiltrating the blower and air intake vent.