Insulation and heat pumps. New houses built in Sweden _above the Arctic circle_ use less than 9000 kWh per year. 300mm of insulation and a geothermal heat pump that gives you at least 3 kW of heat for every 1 kW of electricity.
You can cut that number by a factor of 3, just by building apartment blocks instead of individual houses. It cuts down the heat loss area, and lets you install larger pumps that benefit from efficiencies of scale.
AFAIK, an average flat around the latitude of St. Petersburg uses ~300-500 kWh per month, or 3600-6000 kWh per year. And that's considering that most housing stock there was built in the 70s and 80s.
If we're talking top of the line insulation and a geothermal heat pump, the numbers should be way lower than that even. Not to mention that generally speaking living inside the Arctic circle is a giant waste anyway. You can't do agriculture there and it costs a lot to heat things. It should be reserved for research stations and temporary work establishments.
My point is the insulation is the cheapest way of lowering heating (and chilling) costs.
Also, lots of mining, logging and manufacturing jobs up north.