I wonder if anyone has gone to Lowe's or Menard's to pick up an inverter to provide emergency back up and used it similar to this video:
My frig is already DC and I've tested with the i-miev in the summer. It sips electricity and for the hour or so I had it plugged into the 12v socket I never saw a drop in battery level. The biggest draw would be a portable radiant heater. As I live in a tiny house super insulated a 500 watt heater should be sufficient....