There have been some efforts to make residential geothermal heat pumps price competitive in many markets. In which case, winter insolation with clouds may actually be enough to heat houses.

I would guess that we'll see far more thermal storage (refrigerators, water heaters, etc...) in households as appliances get smarter.

They won't be just because you have to drill a borehole, or two, or lots of ditches >6ft deep.

I don't understand the downvotes.

That's why I went with air-based heat pumps instead of geothermal. Everyone I spoke with told me that it was very risky, cost-wise, to install where I live.

Granted, geothermal might be more affordable in other geologies.