In theory, these could be connected to a new nuclear island, although I don't expect any will to do so. It's probably a very good idea, but one I doubt that would catch on. It is interesting to think they have plenty of valuable used nuclear fuel on site, and, again in theory, these might be reprocessed there to build a series of SMR's that might be added together to drive the turbines from the damaged unit, although it's quite possible they've been cannibalized for parts.
Another option that we should consider would be finishing the construction of Seabrook-2, rather as was done with some of the Brown's Ferry reactors. I've seen the Seabrook reactors, having spent some time in Newburyport nearby, and it does seem that Seabrook-2 might be completed.
I regret to say that when I was a young and stupid antinuke myself, I participated in idiot "activism" in opposition to Seabrook. I helped in this way to kill people and to kill the planet since Unit 2 was not completed, costing lives. It is a matter of some regret.
In my defense, I believed the theoretical bullshit handed out about worst cases, until Chernobyl demonstrated experimentally what the worst case actually was. I was also oblivious to uses of mathematical statistics beyond the narrow quantum applications, and so I was easily sold the bullshit without taking the time to check into things like expectation values, which is now obvious since there is a 100% probability that fossil fueled power plants kill people when they operate normally.