For Sansa you can really write a single chapter with a big cliffhanger, and have her show up much later with a lot of stuff having happened behind the scene.
For Arya, similarly, she just needs to bail out of Braavos.
Sam and Connington would meet at Old Town, difficult to cut this out, needed to reveal Jon Snow's true parentage and what not.
Dany can suddenly show up at the battle of Mereen with her Dothraki army, we can figure that they bowed to her now that she had a full grown dragon, the way her chapter ended was enough to know as much.
The battle of Mereen, because of Tyrion and Victarion, can't be cut too much, especially with all the build up to it.
Then post battle, Dany has to start burning all the sick people alive which will probably lead to her departing for Westeros.
This Dany stuff would take a lot of chapters, but I'd think she doesn't reach Westeros until the end of the book.
The stuff in Dorne leading to Myrcella's death and Dorne supporting Aegon.
Brienne/Jaime/The Hound is all about them killing Catelyn who "survived the red wedding", but not sure how this would turn out, other than Brienne finding out where Sansa is once Sansa is married and heading for her. Jaime probably goes back to Cersei when he hears of his daughter's death. The Hound, I guess he'd tag along with Brienne however that works out.
Cersei's trial, the Mountain slaying everyone and her supporters/troops waging a civil war on the people, which leads to Aegon being supported and taking over King's Landing (and killing the Mountain in the process, has to slay the "monster"), and Aegon becomes the beloved king, marries the Dorne queen.
The mess in the North, Jon's return, somehow all this getting tied up, and Davos coming back by skipping over whatever he did and just summing it up.
Dany arriving at Westeros.
Can this fit in a book? Feels complicated. Leaves a lot to settle in the next book. And it reminds me of how the show ended up having to cut so much to speed things up.
