Coldest for me was 45 below in Saranac Lake. often the coldest spot in the nation.
Next was the weekend my roommate and I went to the Winter Carnival in Minneapolis for our semester break. Did not get above 30 below. What I saw of the Carnival was through a very small spot I kept cleared on the passenger window of an old VW Bug!
Like I said, as kids we didn't have to go to school if it was zero...that was before all the 'wind chill' stuff factored in now a days.
Have a friend raised on a farm in Minnesota who says his Mom would tie a rope around his waist before sending him out to bring in more wood.
Saw a doe and two still spotted fawns just at sunrise today.