Looking out my window watching the plow guy clearing around 9" of snow from the condo lot. High temperature today is projected to be -3F.
Back in my "Dirt Dudes" mountain biking days this weather would not constitute an excused absence. Skip a Saturday and you might have to wear a tutu the next week. Uphills were hard because you had no momentum or traction. Downhills were interesting. Heat from our brakes would melt the snow and moisten our rims. Then cold temperatures would glaze ice onto the brake surface. The only way to slow down was to find some deeper snow to steer into and hope there wasn't something bad under there.
I don't do that kind of stuff anymore.