Fortunately there's a couple (literally 2) gas stations near me that sell ethanol-free 91 octane gas, which has a shelf life of ~1 year. Sta-bil in theory extends that substantially longer. My solution is Sta-bil in the E0 gas, which gets used throughout the year for small engines (lawn mower, snowblower, pressure washer) and the generator if needed. I power up the generator once a month to make sure its battery stays charged and fuel keeps flowing (probably overkill). My power goes out 2-3 times a year, so that combined with the small engine stuff is enough to cycle through the gas in ~1 year, but if it isn't, I'll either burn it in the generator or just run it in one of my cars.

If you live in an area where you can only get ethanol gas, then you definitely don't want it sitting more than 6 months, even with Sta-bil (in my experience). So that means yeah, you gotta cycle through the generator's tank twice a year, which if you live in an area with reliable power, means spending more money than you need to on gas and oil. Also, keep all containers (including fuel tanks) as full as possible, to minimize the amount of air in the container, to minimize the amount of moisture the ethanol can suck out of the air.