Properly sized heat pumps are nowhere near as expensive as many people think. It’s primarily an issue of needed heating capacity bring massively over estimated. Technology Connections has put out a great video recently that goes over it far better than I could, and he has had a similar experience with his parents as I did mine. The HVAC company wanted to replace with a heat pump of the same size as the furnace. A furnace that had at minimum 2.5× the capacity that they actually needed.