The technology improved rapidly between 2009 and 2013. I put a mini split ductless heat pump in my well insulated 2000 foot house in Tumwater WA. I set the thermostat for the heat pump 3 degrees higher than the existing natural gas. I saved about 30% on my heating bills in winter.
The guy who bought the house from me when I downsized says the gas only comes on 2 or 3 days each winter. The kicker is, the DHP was sized for a 1000 square foot area. It’s handled most of the house most of the time.