We haven't been on this ship.
However, here are some thoughts.
If there is a frig in your stateroom , you should be able to unplug it and use your iron without any problems.
If there is a 120VAC hair dryer in your bathroom, you should be able to unplug it and use your travel iron.
The entire idea of blowing a circuit is to not exceed the allowable current at any given instant. If you are replacing a refrigerator with a travel iron, you should be OK. If you are replacing a hair dryer with a travel iron, again no problem.
My final idea, please take a candle and lighter with you in case my ideas are incorrect. If you would happen to blow a fuse, don't worry. The cabin attendants are very interested in their tip and they will accommodate your power outage.
Enjoy your cruise and don't worry about a power outage. The crew will handle it in short order. Don't even worry about plugging it in!! GO FOR IT.
Shirley and Les
