Actually, from my days into classic and even veteran cars, I think that used mechanisms with oil all over them are a better deal through the winter than newly cleaned and serviced mechanisms. I change the Rohloff's oil when in the new season I want to ride it again. The worst thing you can possibly do to any kind of a tank or steel gears running in a shell is to service it and leave it standing empty when you know there will be condensation-making changes of temperature. The only other thing, except to check that there is air in the tubes to keep them from being wrecked, is to lift the rear of the bike up by the carrier and to operate the pedals (or the electric motor, which I also recharge at that time) briefly in gears three and five to cover everything in dirty oil, and to splash it everywhere, and to run the chain through whatever is in the Chainglider. I don't bother to open the Chainglider because I know what is inside, goo from the factory lube on which I run the chain for its entire life.
I even leave a light layer of dust on my bike so I can see if the condensation Martin refers to has formed and trickled down the outside of a tube to...where precisely, so I can determine whether I need to do something about it. A small pot of vaseline is good to have to hand, because vaseline is clean to apply and wipe off again, but be sure you don't plug airways that are supposed to be open.
If your bike is so filthy dirty with wet mud when you want to put it away that it is obviously imperative to wash it first, at least stand it inside in the heating for a few days to dry off the interiors of the tubes thouroughly before putting it in the garage.
Hope you get better soon, Matt. Like Dan says, your bike will be there waiting for you when you're ready to ride it again.
PS Something that rings a loud bell with me is a remark earlier in this thread about mold. Recently I lost a lady's handbag in very high quality sheepskin, that I used to carry paints in on my bike, to mold. One day while I was cycling with my doctor, an old pal, we found a mushroom so large he had to return with the car to harvest it. Sometimes I think that Ireland is the world capital of mold. My Brooks saddle is irreplaceable. I doubt that Brooks can still get leather as thick as that on my B73, and anyway it requires a special quality of leather, also very likely no longer available, to offer the honey colour I started with to make the special brown on my saddle by the judicious, timed application of neat foot oil, that matches handgrips which I toned by the same method, also starting with honey colour. So I check the underside of my saddle once a month too; the handgrips have soaked up so much wax from leather cycling gloves that mold can't get a foothold and anyway they're eminently visible.
