What fuel stabilizer do you use, how long do you keep the gas, and what do you do when it expires?
Every 6 months, dump the stored gas into your car and refill the can(s) at the station. Even better, get a manual transfer pump so you can refill your gas can from your car's tank in a pinch. My "emergency" generator fuel supply is ~16gals in each of two cars.
It's a good idea to fill up before a major storm anyway in case you need to evacuate.