can you fire it up once a week? that would prevent any fuel problems.
Stretch a condom or a surgical glove over the exhaust outlet.
I tend to keep any little silica gel desiccant bags that I find packed in with shoes, handbags, kitchen utensils etc etc, and pop them in the trays and drawers of my tool boxes, to help keep the moisture away. Might be worth your while popping a couple inside some poly sheet and loosely wrapping around your brake discs.
As this list grows it might be easier to just use the bike? Andy