Just speaking for
DCL - If your husband wants to use his phone and laptop just like he does normally, frequently taking and placing calls of varying duration, or downloading/uploading more than a few MBs of data per day, that is not going to happen.
Cell service is indeed pricey for at-sea days, and while voice connection reliability is far better than data, it’s still spotty. And I am guessing you aren’t looking to buy a sat phone.
Port days are different. If you are in the USVI, for example, odds are good that coverage is included in your U.S.-based plan. If not, major carriers offer “cruise packages” for something like $10/day for non-U.S. ports. But the service often caps your minutes, and usually does not include very much data, if any at all.
As others have said, high-speed bandwidth and cruising are not compatible. You will be banging your head against the wall trying to make this work, and it’s really going to detract from your cruise.
I have been there and tried that, and unless there’s a sea change (yes, I said it!) in cruise ship connectivity, I will never try it again.