I have to say I have no idea. What an interesting question!
I live in Finland, and the winters can be pretty rough. There is also a long tradition of building from wood. It would be impractical to build a house, usually with several fireplaces, only for the heat to escape through the ground.
Dirt floors are only used in structures where people don't spend the night, for example sheds. Also, there is an old church from the 15th century with the original dirt floor because of its historical significance.
I live in a Finnish midsized town with a population of roughly 80 000 people. My repair shop offers to drive you where you want to go, but you're in charge of the way back to the shop when they call to say your car is fixed.
It's a great service, and it guarantees my loyalty to that shop!