We usually have an indoor temperature of 22°C (approx. 72F).
Most people overhere (the Netherlands) use thermostat settings of 20°C, but we feel that's just not comfortable.
We use an air/water heatpump. Mitusbishi Zubadan. 11 kW.
We have enough PV to power the house (incl. heating) and car (BMW-i3).
for details, see my (mainly Dutch) website:
geen energierekening meer: energieneutraal woonhuis fam. Kriegsman Ootmarsum - Rekening energiebedrijf 2013