I been known to go 2.5 times regular dose for 2.5 years. I wouldn’t push it much past that although the fuel still looks pretty good although somewhat amber. No black deposits, though, like you’d get without stabilizer.
Had to rebuild a buddy's lawn tractor carburetor last year.
He had it setting up for over a year in his barn, the gas tank smelled like varnish.
Really a gummed up mess, steamed cleaned the tank, replaced the fuel lines and filter.
Chewed him out about not using Stabil, LOL.