Hosta sieboldiana did well for years in a west exposure for me.

Assuming their water needs are met, I believe you may have an excellent site for the blue hosta.

I believe blue hosta like a little bit--but not too much--sun for their best coloration. A couple of hours of direct sun & even several hours of a combination of sun/dappled shade will not stress this plant. They'll do fine in full shade but will look less "blue" and more "green".

NW summer sun (like Bigfoot, is it myth or does it actually
exist) won't be melting the wax off any plant.

My opinion only

There are a number of very sun tolerant hostas. Generally, those with gold or highly variegated foliage develop their best coloring in at least part sun (morning sun is ideal), while the blues or solid greens are extremely shade tolerant and will maintain their color in virtually total shade.

All of my hostas received at least part sun and did very well, but I attribute a lot of that to very good soil conditions. Of the blues, 'Halcyon', 'Elegans', 'Krossa Regal' and 'Blue Angel' are supposed to have maximum sun tolerance.