For us, the gaps between generator run-times is typically 8 months, and there has been twice of 1 year and 8 months. Practicing this for over 12 years and all remains well. The rig is kept indoors which likely helps, but I do feel that if your rig is stored outdoors in a dry climate, it's not all that different from our situation except for potential for rodent and large critter damage.
I should also mention that I never use Stabel or other fuel additive for long term storage, nor any other type of fuel additive such as fuel system cleaners. I hear about Seafoam all the time but really know nothing about it. I store our rig with a full tank of regular gasoline.