Seattle is just 20 miles from NBK as the crow flies. It's reasonable to assume the entire region will be carpet-bombed until completely sterile.

https://en.wikipedia.org/wiki/Naval_Base_Kitsap

"It is the home base for the Navy’s fleet throughout West Puget Sound, provides base operating services, support for both surface ships and fleet ballistic missile and other nuclear submarines as one of the U.S. Navy's four nuclear shipyards, one of two strategic nuclear weapons facilities, and the only West Coast dry dock capable of handling a Nimitz-class aircraft carrier and the Navy's largest fuel depot. Naval Base Kitsap is the third-largest Navy base in the U.S."

The entire Western WA metro area would be completely 100% screwed. You ain't getting over the cascades in a car. You can barely get over it on a regular US holiday. Going north? Yeah good luck fighting with the 10+ million Canadians trying to come south after their own inland routes are taken over by chaos. You could maybe go South and then inland up the Columbia, but then you'd have to pass through the radioactive wasteland that would be the bombed out Hanford reservation