On one of my snow mobiling trips to the Arctic some years ago well north of Finland, the temperature got down to minus 25 degrees Celsius. At that point it was too cold for my camera, and it wouldn't work until I warmed it up in my armpit for a half hour or so. Be careful, then, about the cold and your camera, but in the upper 20s, either Celsius or Fahrenheit, you ought to be OK. Yeah, ditto, let us know how it goes. Safe trip!