I grew up in Montana, same latitude as MN. The entirety of my K-12 schooling was done there. We never once had our schools close for snow, but we did have 2 closures due to extreme cold. Once it was so cold, the school's boilers couldn't keep up heating the buildings. The other, the boilers were going so hard they actually managed to start a fire in the ceilings.
That said, there were days where snow prevented me from getting to school and days where the drive home was treacherous (the only way to tell where the road was the highway reflectors sticking out of the snow). I also learned how to chain up the first year I had my license. Nearly every day in December that year, I had to chain up to get home (water on ice and ~14% grade on the first hill up to the house).
Also in Montata. Our school has closed for one day in 30 years due to weather. This was due to busses not being able to travel the town roads. Our kids would have been at school since they don't ride the bus. They've failed to get to school one day when my plow truck ended up stuck sideways across our road.
That said, there were days where snow prevented me from getting to school and days where the drive home was treacherous (the only way to tell where the road was the highway reflectors sticking out of the snow). I also learned how to chain up the first year I had my license. Nearly every day in December that year, I had to chain up to get home (water on ice and ~14% grade on the first hill up to the house).