This is why I’d characterize it as potentially earlier use of AC: we’re already seeing many people who didn’t previously need it buying ACs so the greater efficiency of most heat pumps is going to be welcome as that trend accelerates. I live in the mid-Atlantic region and our heat pump system lowered our annual electricity consumption even though we got rid of a gas heater because the savings over our old AC in the summer outweighed our increased winter demand (obviously the numbers in winter are worst for more extreme climates but recent years have really brought significant efficiency improvements vs. older AC designs).
The other thing to remember is that summer is the easiest problem: the times when you need it also tend to be when solar is producing well and that’s cheap and easy to deploy. Winter is much harder because its demand has less sunlight and often coincides with cloudy weather.
If the sun shines a lot, we will have a lot of energy we can consume through an AC.
Overall a heatpump will lead to a 2-4 times net energy reduction.
Your normal car can use 30-40% of the energy in gasoline. We could just make energy out of it, use the process energy and drive a heat pump and we will be above 1 kWh from 1 kWh of gasoline energy.
Talking about the south is silly because in most of the southern US it is near unlivable with humidity to go without A/C.