I'm experimenting with a guitar on board for this trip. Soft case, so I can mush it out of the way when the guitar is on its stand. We usually have decent humidity control with reverse cycle, fans, exhaust fans, etc. So far, OK.
This guitar, semi-thinline acoustic-electric, was sorta-kinda selected for being on board. Looked at carbon fiber options, couldn't spare the extra arm and leg. Also looked at the Yamaha silent guitar, which still might be my next choice if this one doesn't work out (space being the more difficult issue).
South River, Chesapeake Bay