I've considered moving back, but honestly, I'm happy just being within driving distance of the PNW. I'm thinking of maybe moving to E. Washington or E. Oregon near the mountains to get a bit of the best of both worlds: lots of sun and only an hour out two drive from the green mountains.
That doesn't really solve the winter months, but it means I would only move south for 3-4 months of the year (December-March).
So for now, I go back almost every year. I'm going for a wedding in June, and two years ago we did a big road trip up there and visited Victoria, BC. Next year we'll probably do another trip there.
But I much prefer the sun, so I'm content to travel.