Gasoline isn't a single substance, like water. It's a mixture of quite a few different compounds. That's why you can have different octane ratings. Butane, for example, is cheap and burns well, so it's a very common component in gasoline. Unfortunately, it's got a really high vapor pressure. It escapes the mixture easily and over time will completely vaporize out of your gasoline. That leaves you with only harder to vaporize and burn components. Eventually, the fuel becomes too difficult for your engine to vaporize and burn. How long that takes depends on the exact mixture and the conditions the fuel is kept in. Winter fuel goes through this process faster, largely due to higher butane percentages. Lower temps help slow vaporization rates. A couple of months probably isn't long enough to have issues with the fuel, but I've said probably before. If you add a fuel stabilizer, the odds of having any issues over a 3 month period drop to almost 0. Heck, you could probably extend that to 6 months and still be perfectly fine.
Ethanol itself won't be an issue a modern motorcycle. It can be a problem for old bikes with different gaskets and hoses, but modern ones were built with ethanol safe components. It isn't a problem. Water, however, is an issue. And ethanol loves water! They are like peas in a pod. Where can you find water? Well there's lots of moisture in the atmosphere. Some of it gets absorbed into the ethanol in gasoline. Over time, it adds up in your tank. Why is water in your fuel bad? Well it helps rusts metallic components, and doesn't burn very well. Two things you don't want your fuel to be like. I suspect a fuel stabilizer can slow this process as well, but I don't know for sure.
Like others have said, a fuel stabilizer and battery tender will see you through the winter. Just make sure it's only one winter. It won't keep you good forever.
Ethanol itself won't be an issue a modern motorcycle. It can be a problem for old bikes with different gaskets and hoses, but modern ones were built with ethanol safe components. It isn't a problem. Water, however, is an issue. And ethanol loves water! They are like peas in a pod. Where can you find water? Well there's lots of moisture in the atmosphere. Some of it gets absorbed into the ethanol in gasoline. Over time, it adds up in your tank. Why is water in your fuel bad? Well it helps rusts metallic components, and doesn't burn very well. Two things you don't want your fuel to be like. I suspect a fuel stabilizer can slow this process as well, but I don't know for sure.
Like others have said, a fuel stabilizer and battery tender will see you through the winter. Just make sure it's only one winter. It won't keep you good forever.