My 4 year old clipper II lives inside a converted cowshed hangar in a very damp humid (humidity up to 100% most days occas dropping to about 65% in the height of summer) corner of the UK (Cornwall).
I have a (2nd hand) industrial dehumidifier (£250) on in the winter 24/7 and it extracts 3-5 gallons of water every 24hrs between Nov and Feb.
I went for the clipper partly because of the extra corrosion-proofing and it seems to be holding up well.
The only parts showing corrosion are the extra night kit brackets that the CAA require for night flying in the UK (Non-Robinson parts) and the very tip of the candy-cane at the tail.
I think the dehumidifier helps and would strongly recommend it for sucking the dampness right out of your hangar and protecting your machine.
SB