The northwest US doesn't seem* to be worse than most of the Europe, where we have a veritable boom of solar power. Granted, it produces next to nothing during the winter, but the yearly production makes it profitable still. Even for well insulated house you need some heating in the north, but it can be surprisingly little. It's not like these houses are going to be built totally without network mains.

*: https://globalsolaratlas.info/