At least "grandpa's gas" was ethanol free. Even if you don't believe gas deteriorates over storage, at least use a stabilizer to help prevent moisture and ethanol separation.
Fuel stabilizer will not hurt anything. At least the name-brand stuff that has been vigorously tested.
Fuel without stabilizer, if top grade, will last at least 2 years without stabilizers.
If you have water in your fuel, or do not top up often in cold moist environments, then you need methanol or a fuel stabilizer rated for water absorption. But you have a bigger problem, and that is your filling habit. FYI: careful with methanol, it can eat stuff.