I've had mechanical film cameras reach an outdoor ambient temperature of -60 degrees Fahrenheit with no problems. Of course film becomes quite brittle, and moisture does condense on them when bringing them inside. Letting them reach room temperature sealed inside an airtight container reduces problems with this. When frequently photographing from cars, try dressing warmly and leaving the car interior temperature close to the outside temperature. Good photography is more about doing what is necessary and less a matter of comfort and convenience.