The proper thing to do is to change the oil just before you park the bike to reduce acid deposits from causing any corrosion on the innards during winter. You would then run the oil in the spring for the usual number of miles.
Having said that, I park mine with whatever miles I have on it, old or new and have never had a problem. Sometimes I change it if it's due. Other times....ho hum. I never add any additives to the crank to keep things clean. If you are using a top quality synthetic, you don't need it.
I do drain the float bowls and sometimes add stabilizer to the fuel.
