I also think good air circulation helps. Nowadays there are these small vents with a fan (I think computer fan type), which is operated by a very small solar panel. This helps when you don't have electricity available. However, don't have any experience myself, so can't give any more details. But just as an option.
You need to run a lead from house to the shed. Dehumidifier is the answer. Motorcycle in the house is a major issue, insurance, fire officer etc. Looks lovely though .
carcoon or similar is the best answer, needs power, but not as much as a dehumidifier or heater, I have my 10 bikes in the largest carcoon and none suffer from condensation, anything metal outside the carcoon does though. you may be able to power the carcoon fans from a car battery (in fact I know you can) it's mains powered but rectified down to 12v for the fans I think, worth checking though.
beware of what your are saying on this thread as its been commented about on another forum by a known so-called hot air expert........... just saying.
Going to give this a try I reckon, my garage is a lock up without power so just got a portable “power generator” off Amazon (it’s a rechargeable battery with 13a out) to whack the trickle charger on every couple of weeks it’s stood. Just been to plug it in and it’s warmed up today so the bike is a bit soggy so a USB desk fan will be my next purchase
