My answers are once again from my experiences.
I find climate changes can greatly affect a guitar. I find humidity is the major factor when it comes to neck adjustments and how the body of an acoustic guitar reacts. I find temperature changes will affect tuning but not as drastic when it comes to how wood reacts.
Temperature changes will affect metal very quickly. Metal expands and contracts with temperature change, thus the strings do this very quickly. I have done a million outdoor shows where the temp will be 80 degree's during the day but drop to 60 just after sundown. The guitar will go very sharp in tuning because of this. The neck, etc, won't change much, even if the humidity changes, at such a short time.
If an axe stays in the same environment, were humidity and temp are pretty much constant, I would think you wouldn't have to do that much in the way of adjustments.
When I was in Allaire Studio's with Rush, during the recording of Snakes & Arrows, I had to keep most of the guitars in a separate room with humidifiers, constantly maintained around 55%. Humidity changed so drastically there, that for the first few days days, after Alex decided to record guitar there and had a whole bunch of his acoustics and electrics sent there, until I realized this, some of his acoustics were unplayable until I could get them in a controlled environment. Solid bodies were not that affected as bad but still had to be tweaked almost everyday.
Dudes, this is were I earn my money. I would fill the humidifiers up with water before I called it night. These were the small units you buy for your house, apartment. I guess being a tad paranoid and wanting everything to be perfect the next day for Alex and Ged, I would set my alarm to get up around 4 or 5 am to check on the humidifiers to see if they needed water.
I know, it probably sounds stupid. I did this for a few days until I had it set with the humidifiers so I could actually get a full nights sleep.
The things you do for money.
The new neck on Ged's main bass is a bit more stable than the original, but not much.
I don't know who would setup his basses at home, before me. I'm sure he has tweaked here and there but if I haven't seen his basses in awhile, it doesn't looked like he has done much or if at all. I live in Toronto and so does he so I guess it is easier for him to just call me and have me come around and do any work he might require, when I have time.