Comment by Tor3

As others said, Norway isn't that cold - the ocean is pretty warm. That does mean, however, that the temperature varies greatly with how far you are from the sea. Go far enough inland and it can get cold. -30C or, even these days, some places much colder, though only for shorter periods now (global warming). Most places are barely as cold as -10C, which isn't much of a problem for batteries. And it's often a bit warmer.