To get a useful answer, you would have to put in more information. How many floors? How many sq ft per floor, what is the R value of your house? How cold can it

To get a useful answer, you would have to put in more information. How many floors? How many sq ft per floor, what is the R value of your house? How cold can it get in the winter? How often is it that cold? Are you asking about air-to-air or ground-source heat pumps? The best thing to do is to get one or more local installers to give you an estimate.