I've lived in the midwest, and in Portland. What many people don't get is that Portland has hills bigger than what people in the midwest would call a mountain. Also, snow in late December is relatively rare. We missed a white Christmas by one day. Only have an inch here where I'm at, but hey, take what you can get.
Not to mention the limited resources municipalities have to deal with these events, since they just don't happen that often. It is more common to see 4WD vehicles abandoned in ditches because they didn't realize 4WD doesn't help with braking or going down a hill. Wanna learn how to drive in the snow? Tackle an unplowed, 45 degree hill littered with vehicles that didn't make it.
The first key to effective snow driving is a light throttle and choosing the correct tyre. Driving in snow requires a tall tyre with a narrow section-width. This allows the tyre to cut through the crust and obtain traction on the hard surface beneath the snow (the opposite of sand tyres)...
And so on. I used to teach this stuff -- https://www.wittenburg.co.uk/offroading/Driving/Snow.html