I'm in Wisconsin, and we've had a VERY mild winter so far. We've stayed "positive" this whole winter, only dipping into single digit temps (in F) for a few days. That being said, it is not uncommon for us to have stretches (3 days) of below zero temps as the high, multiple times in a winter! -5F, clear roads, light wind? Schools open, work as usual. If it's windy, so -30F wind chills, schools will probably close, but not workplaces. Welcome to the "north". I'd venture that North Dakota is even worse than Wisconsin, so any anecdotes from a North Dakotan would be welcome for comparison.