Growing up there was a channel for Pacific Northwest news which used the WA, OR, ID definition, which I feel was the most common one growing up in the region.
NWCN channel 2. I remember that!
I tend to think of it as Cascadia minus the Canadian and Alaskan bits- Washington, Oregon, Idaho, Shasta Cascade and Emerald Triangle regions of California, Montanan Glacier Country.
The southeastern part of Alaska really does have an awful lot in common with costal parts of Washington and Oregon. And while the Vancouver area is the only part of BC I've been in, it really did remind me a lot of WA.