the only place I have to put it is in an unheated garage Any advise or opinions good or bad?
It's not ideal but I admit I've stored my collection in conditions like that for years with no problem and only mild preventative measures.
The reputed moisture conditions are not from the cold. They're from either 1) relatively rapid variation in temperature causing condensation 2) humidity. I'd check for those first. Frankly humidity is a problem that gets worse with warmth anyway and rust will be more active the warmer the temperature under otherwise identical conditions. Just think about rust browning procedures
The steps I take are to oil and wax appropriately and place all guns stock up barrel down avoiding contact with fabric which acts as a moisture trap and rust enhancer (DO NOT STORE IN GUN CASES). I use normal cleaning/lubricating procedures with nothing more with a light coat of Renaissance Wax on the barrels and lockwork. Renaissance wax avoids oil/wood contamination problems and stays in place.
I'd love to have a large gun room for display but that's never going to happen (at least as long as I stay married : ) )so I make do with what I can.
Jeremy