How is the heat delivered? Forced air? If so no problems with heat pumps, the modern air source can produce heat at very low outside temps and a ground source

How is the heat delivered? Forced air? If so no problems with heat pumps, the modern air source can produce heat at very low outside temps and a ground source is excellent in very cold climates (if you have artesian well, or ground loop). The problem is most oil or gas fired heating systems are forced hot water (or steam) so a heat pump isn’t going to help you unless you want a mini-split in every room. Even if you have ducting for cooling with AC it likely won’t have enough CFMs for heat in the winter unless it was specifically sized that way (but you likely wouldn’t be still using forced hot water or steam in that case).