State Farm - 30+ years for everything.
Regarding insurance year 'round, motorcycles and RV's are like that just about all the major carriers. If a tree falls on your RV in winter...insurance won't pay. Water damage during storage? Won't pay. We had water damage on a TT back in 2003/4 winter. Insurance wrote check for $3,500 after RV dealer said how much to fix. Would not have paid without insurance.
The motorhome is the first RV we've financed in 20+ years of RVing. Still, I keep my insurance on stuff, stored or not.
If you had a motorcycle in your garage over winter, and no insurance because not using it, and garage burned....well, it would only pay for contents up to a certain amount (tools, motorcycle, stuff, etc. all combined). Best keep it year 'round.