It's been my experience that shit happens. So the 3 or 4 months all of a sudden turns in to a much longer period of time. Why take any chances? Why risk water in the fuel? It has been my procedure for s very long time, to use Marine Grade Stabil AND Yamaha Ring Free Plus, in EVERY tank of fuel. AND...I don't ever use ethanol free fuel, because the specific gravity is not what the fuel sender in your boat is designed for, and your fuel measurements (fuel gauge, fuel used, gph) will all be wrong. I do agree that a few months is not a concern for fuel burn capability, but a few months of fuel separating or even attracting outside moisture=BIG problem.
And to answer your winterizing question...the block is self draining, the reason we rev the engines is to move excess moisture and vapor as far down the exhaust section as possible, to prevent internal corrosion. Fogging hour engine regularly, using Ring Free, and evacuating the vapor from the engine, all the time will keep your boat winterized. And even during the season, changes in temperature and humidity does damage. Using these procedures year round have been very effective for many Yamaha owners for years.