Hey RobRxn, I live on the west coast of Canada. Rain is pretty much every other week here

There are brand new cars sitting on car lots with rusty disc and drum brakes. I will admit it can be an eye sore, but it is a non issue.
Brake pads are super abrasive. When they clamp down on the disk, it shaves the top layers off and occasionally will leave even tiny ridges. This also removes any protective coating that have been on the surface of the brakes. After driving the car any distance, your brake disks are now exposed metal. Even a humid day will cause the surface to rust. The only way to limit the rust build up is to park in a garage.
Even if your car sat for a month or even 2 months, the rust would be a non-issue.
this is probably not the answer you wanted, but I hope it at least rests your mind.