In 2001i was working for a HD dealer in Washington. We had a Road King with an issue. I drew short straw. When I left the shop it was snowing and I had to ride to Canada and back with a side hack on it. Don't remember how cold it was, but I remember it was miserable. I'm so glad I'm back home in California.
I rode 13 miles at -10 when I was 17. But I had fully insulated coveralls and other cold weather gear on. I am not what you would call a fair weather rider, but I prefer that the temperature be at least 45 degrees in the early morning before I start my season.
Somewhere just north of 0F, actual temperature, in Kansas one Saturday morning. That was really cold.
The windchill you experience while standing still is irrelevant on a motorcycle where you make your own wind while riding!
Long time ago I had to drive into a -25 degree wind. I had a Ford with a carb. The thing got so cold the moisture in the gasoline turned to ice inside the carb & it died. Had to block-off the radiator with cardboard & put two cans of dry gas in it to keep it running...
NO TAN SKIN YOU!!!!!!!!!!!!