Searching the forum I find that it's generally recommended you change oil before storing your bike for the winter to prevent acids in used oil from attacking internal engine surfaces.
Other than to prevent an attempted forgetful oil-less start in the Spring, is there any reason to even bother replacing the oil until you plan to run the bike again? i.e. why not just leave the oil out since it will only sit in the bottom of the engine anyway, and cover your ignition switch with a "NO OIL" reminder post-it?
Well, I'm no mechanic, but the oil in there will at least prevent some oxidation (rust/corrosion) of metal for the serfaces submerged.
Cheers
-Denis S.
As a mechanic, oil in there will at least prevent the gears that are submerged from rusting together and keep the clutch friction plates moistened in oil, and the clutch plates from rusting altogether.
Replace the oil with something thick, a heavy weight oil, and run the bike once a week. Just make sure you switch it back out in the spring. If you have new oil in there already just drain it and save it until spring.