Exceloft is not that warm. That's comparable to a 100g Primaloft One jacket, such as the First Ascent Igniter.
I think the Igniter (or similar) is the perfect jacket for the PNW, excluding some gnarly winter adventures. Have you checked that out? I think it's the best First Ascent product.
The Peak XV is serious. It's a monster of a winter down jacket, probably overkill for anything in the lower 48.