-10deg winters are certainly going to put a stop to much walking or biking, regardless of whether that's Celsius or Fahrenheit.

Not much of Europe ever gets that low though. Edinburgh occasionally overnight, but it's rarely below about -4c / 24f during commute hours. Berlin mostly the same, Stockholm's maybe the only big European capital that gets to "walking for an hour stands a serious chance of killing you" temperatures for days at a time.