I start running stabilizer Sept 1, fuel burn decreases and then all gas is good.
Fuel starts to age the moment it leaves the refinery. If you wait til winterization time, that fuel has had time to degrade. Many variables but most agree fuel has fallen off by a grade in 2-3 months. So the portion of fuel left in your tank from earlier fills has now degraded.
I try to change my oil end of season but don't get wrapped up that it is the last thing done before putting her to bed. Every time an engine is brought up to temp, any moisture is driven out and our boat motors get hot every time we use them, unlike grandma's engine that sludges up because she only takes 2 mile trips and never properly warms.
Fog through the intake is sufficient for most winter layups (or none at all if it is short time and kept dry). When I do fog, choking it down as the coolant is sucked in. Fogging the cylinders is good protocol for LONG periods but be prepared for fouled plugs in the spring. Personally, I would not cylinder fog unless layup was planned for a year or more.
Definitely pull plugs to drain water then antifreeze and pull plugs to check it ran completely thru system. I go ahead and drain antifreeze. The anti corrosion properties of any liquid left still protect the motor as it sits and there is no chance of a dilute antifreeze mixture freezing in extreme conditions.
1991 MariStar 240sc, 454, tower, WetSounds, Krypt and Rockford Fosgate