So, Ken, is the garage below grade? If so, that will help moderate the ambient temperature to some degree and the fridges should be pretty well able to work; if not, then in the heat of summer, they may labor a bit (but should be fine) and in the winter, you may need to add a heat pad to keep them above freezing (or at least that is what I do, using a temperature controller). Just don't leave the garage door open in the winter - that is the only thing I have to watch out for when we get the really cold winter nights and days - I live in northern Illinois, as well.