A guy I know has a 14 KWh Tesla battery hooked to his solar system. Hasn't used any utility power since it was put in in June. We will see how well it carries through the winter. He's not expecting it to be total coverage since Nov, Dec, Jan tend to produce less power than is used. But if there is a power outage, he is all set for the basics - well, lights, refrigerator and freezer.The off grid cost will go down as Lithium ion batteries become more reasonable.
Here the Tesla battery is being used for that purpose

Oh, and forgot sage! Have to smudge the house in sage or sweet grass! Keeps evil spirits away and welcomes the friendlys! 