So I love that you took pirates! I was about to write a second adventure about a hidden grotto filled with undead pirates.
What I feel you really suceed with is creating your own battle rules, which will hopefully speed battle up when there is only one hour of play.
I'm a little confused with how many Pirate Ice Cutters I meet in 4? And if I just go from 1. to 2. to 3. to 4. and so on? Also when Ingrid is introduced, does this means she jumps our ship?
I would probably just make som GM rulings on this because I feel like the theme and the flow and tempo of this story really works, so I wouldn't mind just inputting things. I would probably also have the PCs joined by a hireling who could fall into the icy water – because someone has to, right?
Great job!