That's a trick the Germans will have to do about 50 million times to get rid of their gas dependence in all their households. That's going to be bottle necked on the availability of heat pumps and trained people to install those. It will be interesting to see how quickly that industry can scale.
Providing the electricity for those pumps is the easy part of the problem. That just requires doing a bit more of what they are already doing at scale, which would be installing wind and solar all over the place.
In Norway (of all places), the use of fossil fuels for heating was banned in 2020. Not all houses have heat pumps, there are ovens for sale that do not require those. Heat pumps do make sense when energy prices are above some threshold, though, but houses can be upgraded with that over time.
In any case, not all heat pumps are that expensive, and it is also possible to have hybrid heat pumps and air conditioners.
Had Germany decided to phase out natural gas for heating in 2014, and replace it by nuclear power, ovens and heat pumps would definitely be able to keep up with the reactor build rate.
Providing the electricity for those pumps is the easy part of the problem. That just requires doing a bit more of what they are already doing at scale, which would be installing wind and solar all over the place.