Good thing you’re not driving over the Sierra mountains through Nevada, we’re having a Donner Party weather year!
That said, driving through any part of the country with snow, it’s best to have a couple 50 pound bags of sand in your trunk. One bag over each back wheel. Adds weight for traction and if you do get stuck , just pull them out, spread the sand in front of all four wheels, and drive away.
I am explicitly trying to avoid mountains wherever possible.