The shifts back and forth from hot to cold, and themoisture fluxuation and or its freezing within the mount cause the problems sighted above.
Dry or moisture regulatedcold alone won't hurt a mount once it is dry and stable.
A garage with wet autos coming in and out spewing acitic and and sooty fumes, add to the problems of constant changing temperatures.
Throughout the midwest dermestids which are a variety of little beetles and their larva are in epidemic proportions. These little bugs eat feathers, hair and fur, along with nearly every natural fiber and protien substance. They live in firewood and other things you bring in and out of garages and will readily infest mounts.
Likewise storing mounts in dark damp basements will encourage bug, mold and mildew problems.
While not a perfect solution explaining to your wife how much the mount means to you and that there are statistics that show guys that are happy hunting aren't out running around on their wives might be an option!
Mike
www.mikescustomtaxidermy.com