I've never been on a quilting cruise but I have cruised. I found it to be a great way to tour an area. I am thinking you will sew on the out to sea days. When you are in port you will want to go ashore and sight see or shop. I understand there are some great quilt shops in some of the Alaskan ports.
My cruises have always been to very warm locals (Caribbean, Mediterranean, and Mexican Riviera). I have never done an Alaskan one but I bet the sights are amazing even if the weather could turn chilly. I would jump at the chance. Plus cruises are such a great way to unwind. You don't have to worry about a thing. Crew takes excellent care of you and the food is always wonderful.
I know this subject has come up here before, you can use the search feature and I am sure others who have done a specific quilting cruise will chime in. Do you know what teachers will be on the cruise your husband is considering? That can also make a huge difference in all that you get out of it.
Here are links to a few
https://www.quiltcruises.com/cruises/Alaska-2018/
https://stitchinheaven.com/alaska2018-1-quilt-cruise
These links can provide you with a lot of information as to what you may experience.
Edited to add a couple links to other topics on quilting cruises I just found using the search function.
Has anyone been to: Quilt Camp at Sea?
quilt cruise