I'm with Denny on this one. My truck sometimes sits 1-2 months, sometimes is driven twice per week. I buy gas wherever I'm at when I run low, never add any additive. I've been doing this for about 14 yrs and never had a problem.
I have my dad's 1967 lawn tractor that is on its 3d engine but with the original carb that has never been apart. This carb sat with gas in it for about 10 yrs before I put it on the 3d engine. All I did was empty out the old gas, put it on the replacement engine and start it up. I now use it with a garden cultivator and it starts on the first crank.
I think there is as much erroneous ethanol information out there as there is correct info.