I'm guessing you're not going to get more than a day or two out of a battery backup, but of course it depends on your battery capacity. As for recharging those batteries with solar panels, well, it could take a lot of solar panels. Still, worth figuring out if you want the green and self sufficient option.

Me, I have oil heat and a 500 gallon (underground) propane tank hooked up to my generator. It automatically switches on in less than a second most of the time, and I don't know how long I could stretch those 500 gallon of propane, but I'm thinking a couple of months.

Peace of mind, and since it only runs when the power is down, it isn't like it really uses that much propane.