I decided against a whole-house generator. We are in an area with a very reliable power grid and only lost power twice, that I can remember, in the past three years. One was only a couple of hours. The other one was a big one. We were out of power for a day and a half. It was a particularly bad storm.
I opted for a small, lithium-ion back up generator. I figured it will run the tank I have for several hours with everything on. Heater alone for a couple of days. I also got a couple of high capacity power banks (20k mAh) as they can be used to replenish the main unit. I might buy another one of those back ups once I have a chance to test this one. That should set me up for two days of back up.
I opted for a small, lithium-ion back up generator. I figured it will run the tank I have for several hours with everything on. Heater alone for a couple of days. I also got a couple of high capacity power banks (20k mAh) as they can be used to replenish the main unit. I might buy another one of those back ups once I have a chance to test this one. That should set me up for two days of back up.