It's cheap insurance and don't want to be the one to blame for someone ruining their gasoline but winter storage is short enough to go without fuel stabilizer.

I've had cars sit for 2 years and have no fuel problems. 5 months in a garage only requires storage on a full tank to avoid condensation in the tank.

Cars that do not make the mileage interval for oil changes should have the oil changed before storage. Contaminated oil should not sit in the engine for 5 months.