Winter cold isn't bad for the bikes...not much corrosion occurs below freezing. Its the late fall and early spring that creates rust problems for me in my unheated shed. Cold nights, then early morning fog (high relative humidity) and I literally find metallic objects dripping with condensate/dew in my shed. I resort to a fan. Greg, anything as good as you describe should come inside if your garage is similar.
Ed Kasper
Detroit