I live in Maryland and I didn't put my bike away last winter, I rode it every month and kept the chrome polished with McQuires Chrome Polish, didn't have a problem. I suspect that if you do the same even without riding you'll be fine. I personally wouldn't spray it with WD-40 or anything else not made for chrome. Just polish it and you'll be fine!
The Flag on my bike honors those who serve our Country and those who have served!