Manjushri

I have generator that automatically kicks on when my power goes out. It shuts down the grid connection before it does so to avoid feeding power back to the grid. You just need something similar that would cut off the grid when the power goes out and switch to your battery.

It should, but it would depend on how it can spread. You might be able to track it into your house by walking through something outside and then wearing those shoes in the house. We have chickens and, since cats are vulnerable to highly pathogenic avian influenza (H5N1), I always take my shoes off in our mud-room were the cats are not allowed. I want to minimize the chance that my indoor cats might be exposed to it.