So, it's not in the book but in a WoJ, if you donīt want to know, stop reading!!
JB was said in a recent Q&A that you can release only some aspects of a Demonreach prisoner (for instance, if you had trapped Vadderung you could release only his Odin aspect and keep Kringle sort of a host). Then, he was asked if Harry could leave the Winter mantle trapped and he said theoretically yes, but it would be complicated, like doing a brain surgery. But I am wondering what else could be done. That is what I thought:
1) If Molly willingly allows herself to be trapped, perhaps she can be released while the Lady Mantle remains. Problem, that would weak Winter and I don't think the WK mantle would allow it, but, what if Harry wears iron while doing the binding? Then, the WL mantle would be bound to Harry and perhaps he could blackmail Mab (not wise but possible) into releasing him of the WK mantle and leaving he and Molly alone, as a price for the Lady mantle to be released.
2) Thomas? Trap the hunger? (in his current state, probably won't survive, but in another occasion)
3) Separating a Fallen from his host? (I don't see Marcone surrendering to Harry's will but who know, perhaps they can make a deal)
4) The one I see more probable: A nemfected from the infection.
