Technology

First off, as the other poster replied, that isn’t true about modern heat pumps. They continue to work below freezing, and many support an “eheat” resistive heating mode, obviously only good if you still have electricity, but that’s true of all heat pumps. Generators or solar+batteries become much more important.

But the beauty of heat pumps is that you don’t need to install ductwork. Look at mini splits. You can do zoned or single room installs. No ductwork required. One of the huge upsides of mini splits are you do get “instant” zoning. You can stop heating and cooling unused rooms to a human comfortable temperature.

You can also get systems that retrofit into existing forced air ductwork.

I wouldn’t be surprised if someone made or will make a heat pump water heater for hydronic radiators.

You can also run the element that is typically outdoors inside if you have enough space in a basement, for example, which stay a pretty consistent temperature all year long.