It depends on the storage conditions. Here in WI leaving the battery in the garage all winter with no tender is a great way to sulfate your battery. Bringing the battery indoors helps greatly, but sulfation can still occur if not maintained. Sulfation occurs when the battery voltage drops and the chemical reaction slows down. The sulfur (from the sulfuric acid) will slowly fill up the pores on the lead plates, further reducing the chemical reaction.
I do not like starting my bike unless I absolutely have too. I put in fresh oil before storage (just cheap oil) and try not to start it until spring, where the oil is changed again. Used motor oils can be very acidic and start slowly eating away at seals. Granted with synthetics this is minimal, but I feel that oil is fairly cheap and this eliminates a possible variable. If you do run the bike in the dead of winter, make sure the oil is close to operating temp. In 20F weather a 15 minute ride will get the coolant to 160F, but the side of my oil pan was barely warm. These bikes are not designed to run in freezing temperatures, and doing so is a great way to plug up a breather line that is trying to get rid of more moisture than it was designed for. As my dealer said, winterize it, charge it, leave it until Spring.