Sorry you're having such a hard time
This is just a thought, and might not be workable for you, or you might already be doing it, but if Izzy is starting to PT, could you maybe try and get her to use the potty just before bed? And limit drinks after dinner?
Being dry at night is very individual, and has no relation to training in the daytime as far as I can tell. Ds1 day trained at 22m, but wet at night until he was 6. Ds2 day trained at 2.5 and was simultaneously dry at night. Its one of those things that just happens when they're ready!
In terms of nappies, pockets were definitely the best for us at night at this stage. Minki and Happy Heiney were the ones we used. They can be stuffed as much as required, and were very reliable. Depending on what you stuff them with you don't need many as they dry very quickly. A pad folded terry square is pretty absorbant as stuffing goes, and dries very fast. You could probably manage with only 2 pockets if its just for nights.
Or... could you use your current NN with a little more boosting and a PUL wrap? It could be that the wetness is wicking through the wool with pressure, especially if she is sleeping in one position, and a waterproof wrap might contain it better? We gave up on wool at night for this reason - heavy wetting boys lying on their tummy in wool = wet bed and dry bottom