Last year I went over 6 months with customized widebody quarter panel & other parts in raw metal & went to weekend car shows, etc with it exposed (Rain also)before epoxy last fall. Cleaned by sanding, rotary wire brushing some parts, wiping & more sanding as a final not to have any smeared metal from brushing..
Handprints are the worst & going to a church sponsored car show where an unreal number of people not only touched, but were just rubbing all over the freshly cleaned raw metal was my inspiration to find time to get back to bodywork. Something about custom shaped raw metal draws people to feel it, even my wife did after my countless fussing about others doing it.

To date I don't know of an in between protectant. I'm in a usually horribly damp southern environment, yours would be minimal cleaning. Never tried it, but another thought would be some of that self clinging plastic food wrap. Would help keep the oxygen & especially handprints off.
Overhead infared heat can be the best type when having to run fans as it heats objects rather than air & will warm the concrete which will radiate heat back.