I received this email from Auber Instruments regarding minimum ambient temp :
1) For the plug and play controller for electric smoker, the sensor has to be above 32 to read. You can use you hand to warm up the sensor to get it start. the controller can be at any temperature.
2) For the plug and play controller for charcoal smoker, the controller itself has to be at above 20 to function correctly. The sensor can be at any temperature.
3) for component type controller, the controller need to be above 32F to reading accurately when thermocouple sensor is used. It can display a reading when controller is below 32F, but my not be very accurate. If will display error when controller is below 0F. The sensor can be at -200F.
4) For component type controller with RTD sensor connected, the controller and sensor can operate to at least -40F accurately. But we have not tested below -40F. Some model may not power up.when temperature is below -40F.
I guess my next question for those of you in the colder climates is what type of sensor do you use, a thermocouple or RTD sensor?
I am currently converting an old frig to a electric smoker Thanks to those who replied to my thread