The garage is probably not the best place for them unless you sealed it off and converted it into a livable space with heating. If you are using the garage for cars though, that wouldn't be possible.
Is there any way you could talk with your wife about this? The garage is not a livable space for any animal, especially one that is native to Equatorial Africa..
I beg to differ on this. In the state of Michigan my buddy has his garage for all his snakes heated and insulated. if done properly anyone can use garages/sheds for any reptile in general