I have this problem also. I have to crawl over the bikes currently in my garage. I want to have only the bikes I plan to work on this winter in my garage. Fortunately, I have some space at my downtown office that I can access through the back door of my building. In the past I have stored 4 bikes here, but this winter I plan to pack them in like sardines so I can focus on the projects.
I have to drain all gasoline out of my bikes when I store them in my building (fire insurance).
The big bummer for me right now is that "projects" include my XL250 which I want to get at least running decently before I put it away, the Ebay bobber which has some new carb jets on the way and I want to install, test and tune them before it goes away, and my flat tracker which I wanted to change the tank (I guess that can wait).
The Chang Jiang will probably spend the winter outside under a cover, unless I can persuade the in-laws to store it in their barn.
Peace & Grease, Dennis