After a night where the heat and my cpap used too much power (heater locked out) I went with a portable cpap batt. I can get about 14 to 18 hours cpap on the portable. Cheaper than adding more house power, and still keeps DW, DD, and pets cozy. Leaves enough AM power to run Keurig off inverter. DW cold and without coffee is not a place to go...
My cpap setup is about 3amps avg, no humidifier. More than what estimates say...
The portable batt has more than enough power to be my cell backup too.