The energy mix for electricity in Sweden, Norway and Finland is mostly made up of hydro+nuclear+wind, especially wind and hydro complements each other very well since hydro is very much on-demand and can cover for most temporary wind shortfalls.

Driving through my childhood area up north a few weeks back I was also surprised by the amount of solar going up, for comparison this is an area _north of_ Anchorage/Alaska with less than 3 hours of sun around Christmas, but already by late January (usually the coldest period of the year) there is over 6 hours of sun a day (so with high pressure cold peaks with less wind, the 6 hours probably eases the power bill quite a bit).

An interesting fact about those solar installations was that the panels were mounted almost vertically (probably to avoid being snowed over but also useful in the winter since the sun mostly just shines from the south anyhow).

Solar would produce enough power in winter. Germany is europe's top solar energy producer and is at a latitude similar to Alaska.

North Americans mostly do not use electricity for heat in the winter. Around 60% use natural gas with forced air furnaces. Something closer to 80% have the option, but 20% don't bother to use it.

Some of the deep south get by with electric heat, but they aren't in places where the cold is a typically a legitimate danger to health and safety.

Supplement w/ geothermal?