Interesting problem.

Abandon car with some survival items onboard to walk out carrying items. You're more or less at the mercy of the crowd there. You are a have, they are the have-nots.

I think I would try and get off the road ASAP, parking the car on the side, then get over/through a fence if needed, and make my way home on the surface/secondary roads. Could be problematic. While I've only been to the PNW once, I know the type of roads you mean.

In this case, the radio may be the most important item to have, short term. At the very least you could find the source of the problems and any expected solution times.