Tharvot
Crusader for Truthiness
I confirm the above statement. It was frustrating having to read those chapters. I put them on a lower level than the chapters on the iron islands characters.
But remember books 4 and 5 happened in parallel. I wouldn't be surprised to see them scrap a lot of characters from book 4 and instead opt to do the two books together in one season.
If they pair down the final 2 books, the show can cut out quite a bit w/o missing any big events. As you said, the books are written awkwardly with 1/2 the characters being in book 4 and the other 1/2 being in the first half of book 5 acting simultaneously. However they get it to work, I'm sure it will be great. The show really is high quality and as of now, my only concern is Martin's writing pace and whether or not he can stay ahead of the show.
It would be absolutely ideal if he could wrap up his next book by the end of this season (not gonna happen), but I wouldn't put it out of the realm of possibility that he can finish up and have the book released just prior to the start of Season 5. That should bolster both his book sales and the show enthusiasm...it should also give him a few years to wrap up the series.