There are breathing help for that, feels like a cold summers day. Well, that's what the article is about after all so I guess you guys know about it :-)
I studded my own tires by putting screws through from the inside out.
Frostbite can be a problem if you stand still or if it's really windy, but usually not something to really worry about. Not only did I ride to work every day for 3 years, I also went for a walk every single day at lunchtime to get sun on my face. Walking, outside, past -40C is really no problem. The days the wind was blowing from the north and the windchill was past -65C were a different story.
The colder it gets the more people are out. I rode my bike to work every day of the year, plenty of times past -40.
Friends were advised not to go running at -55C (-67F) because it can freeze your lungs. So they went walking instead.