I hope things have changed. 10 years ago when I rented a house with a ground source heat pump each winter was terrible. The frost depth here defined by building

I hope things have changed. 10 years ago when I rented a house with a ground source heat pump each winter was terrible. The frost depth here defined by building code is 60". I imagine that system had been burried much too shallow to be effective. Which brings me to my point: the colder a region is the further down in the ground you have to dig the more costly that excavation rapidly becomes. Ground-source heat pumps are not a competitive solution for cold places in terms of up-front cost.