Yes, of course if they're bi-directional. And theoretically, you can also use excess renewable power to heat up the soil in summer and draw on that stored heat in winter.

-20 - at which point the COP of the heat pump I linked to is still well above 1 - is equal to the coldest temperature on record in the locations I mentioned. Not the coldest daily maximum. The coldest temperature ever recorded, and the heat pump still wouldn’t require any backup system. Yes, it’s probably working hard at that point, but so? We’re talking exceptional conditions for the location.

And for the other 99.99% of the time the heat pump is so much cheaper to run it’s not funny - and in the long run you save even more when you’re not paying for all that gas infrastructure to be installed and maintained.

Sure. A heat pump only needs to be 170% efficient to make back the generation losses. As for infrastructure losses, natural gas distribution has leaks as well.

Also, if the power plant is integrated into a CHP system to heat nearby households then generation gets back some percent.

Heat pumps are dramatically more efficient. A good gas furnace is 95% efficient. Meanwhile, a ductless heat pump can be 300%. They more more energy than they consume. That's the huge advantage.

Converting gas heat to heat pumps, even if they have a gas heat backup for worst case days in northern latitudes, would still be a big win in the net environmentally.