Now, Wednesday, we'll be < -20F, which is cold, but nothing we haven't dealt with before and nothing entirely out of the normal. If anything, winter has been abnormally warmer for us.
I grew up in Mitchell, but left about 30 years ago. As a youth, I had a paper route and vividly remember walking backwards on some cold days to keep the wind out of my face.
Good luck with this upcoming cold snap!
About the south: I used to stay for a while in Austin, TX. During winter we had temperatures below freezing (just ice, no snow). The locals told us that this happens at least every other year. For this some were suprisingly unprepared though, in particular with regard to driving skills, water pipes and building insulation.
Last year it even snowed here. Twice. Nothing major, just a thin layer of snow for a day or two, but the schools shut down. When I lived in SD a light rain would lead to everyone driving 20mph below the speed limit on the freeway.
It's colder than it typically is almost everywhere, so for people who live in the north it's a big deal. For people who live in the south and don't plan for freezing temps... also a big-ish deal.