It might depend on what the quilt frame is made of - wood might swell with humidity. If it's metal, then I think that I would wax it up two or three times a year as a pre-caution against the humidity.
Whether your machine goes on/off the frame easily is also dependent on how heavy it is. A smaller dsm, no problem. Moving a heavy machine quilter in and out of the house will probably get old fast.
Having said all that, I suspect you would have the same issues with the hot, dirty garage that has no view! Try the 'room with a view' first.