From what I remember, you're not supposed to iron in t he room, although a few times we used a dual voltage travel iron to press some clothes. I'm sure your cabin steward can get you extra hangers; I've asked a time or two.
I found a way to travel with few wrinkles in my clothes.
1. Use items like books, folded items like rain coat, etc on bottom of suitcase, then layer jackets, gloves, etc. Then layer pants criss cross with legs on all 4 sides of the suitcase, or at least 3 sides. Then take all or most of your jerseys/sweaters and lay them out on a bed, one on top of the other, and place all together on the criss-crossed pants, then fold each leg over the tops, and there should be no wrinkles in the pants and few wrinkles in the tops at destination.
Another way is to place one pair pants on a hanger, on top of that place a shirt/jersey/sweater. Take off hanger and lay both together flat on the bed, where you would fold, place a pair of underwear and pair of socks. Fold the jersey/pants over these smaller items, and place all in a plastic travel size zip bag. I had 4 perfectly wrinkle free sets at my destination, on May 19.
Also, I carry about 6 pant hangers (from cleaners), and if necessary, two plastic hangers from pants/skirts (I get these when I buy these items), then throw all away at the end of cruise/tour.
I know I answered more than what was asked, but sharing travel tips is sometimes helpful.