I live in Canada in an older home with terrible insulation. Out two tonne heat pump works just fine even at -25C this past winter. We still have a natural gas

I live in Canada in an older home with terrible insulation. Out two tonne heat pump works just fine even at -25C this past winter. We still have a natural gas furnace but our gas usage is down 65% despite this winter being colder than last year’s. Tell me again how heat pumps don’t work in colder climates?