Well, I live in North Carolina, so “really cold” by your measure probably feels like Antarctica to me.
I will freely admit that I am a wimp about cold weather. It’s why I have vowed I will never live up North again if I can help it. I moved back to my home state of NC after a sojourn to New England years ago and have never looked back!
I was stationed at Grand Forks for about eight years.
The temps dip below 0 degrees in December and usually don't go above until the middle of February. It is common to have a few weeks of -30 degree temps and one time we had -40 and below. Brutal but you can manage if you keep a positive attitude and get out to do things.
Just go shopping and out to dinner a couple of times per week so you do not get "cabin fever."
The summers are really nice but short. The local swimming pools open the first week of June and close the last week of August; along with the Garden Centers.