Does anyone have any links to where a person could purchase an enclosure heater?You should install low voltage thermostatically controlled enclosure heaters which can help lift the temperature inside the enclosure to more than the -40C outside. These small PTC heaters can typically be as high as 15Watts, so be careful with the choice of cable.
Probably easier to list those we haven't used, but here goes the list we do use.George,
Thanks for the sharing. Could you please let me know which Mikrotik products have you used in such a low temp environment?