Girlfriend is from Cincy she says single digits every winter...less than ideal
How is salt lake and Kc?
I think this is where we go back to everything being relative. Your gf knows better than I do since I've never lived in Cincy, but does it hit single digits once or twice a year, or does it stay in single digits for weeks at a time?
One sentence answer to your question: if you have kids, the threshold for them calling a snow day at school in STL or KC is pretty low.
St Louis (STL) and KC both get some snow every year, but usually not a ton, though every once in a while you'll get a pretty good storm. Quite a few days below freezing during the winter and maybe a few days in single digits, but I don't remember ever having any long spells of weather that cold back when I lived in that neck of the woods. The sketchiest part of winter there is that you can sometimes get ice storms where there will be rain that freezes overnight, which doesn't really happen as often in the colder places because there it goes straight to snow.
Since you asked about SLC (Salt Lake) and I happen to be familiar with it I can tell you about it, though it is not at all part of the Midwest in spite of what some people in my current coastal city seem to think. Winters are much more wintery than any of the cities I've mentioned. You're in the mountains. If you're in the city itself the snow isn't too bad. More than the other cities I mentioned, but usually colder (and therefore more manageable) snow so it's really not bad. Way better than the snow I used to get in the Midwest or where I currently am (which is wet, thick and heavy, as opposed to light and fluffy). If you go into parts of the city or suburbs at higher elevation you start to get significant amounts of snow. It is ski country, after all. Because it snows frequently, local govt and people can handle it comfortably and it's really not bad, unless you get up into the mountains, but then the trade off is that you get to do fun stuff with the snow.