Yep. I agree with this. They should just have Book 3 take up two entire seasons, with the Red Wedding happening near the middle of season 4. Rushing to get the Red Wedding into the end of season 3 would put off viewers and force them to cut a lot of stuff.
Plus then the rest of Storm would only be like half a season at most in season 4 and the second half would be the start of AFFC/ADWD, which would just be really, really bad pacing. All of the ending parts of ASOS are perfect for season endings. Maybe they could end season 3 with Jon escaping from the Wildlings and running for the Wall and Dany sacking Astapor.
I disagree with putting the Red Wedding in Season 4. Ending S3 with the Red Wedding is the perfect thing to do. It doesnt even have the be the last scene or anything. They can easily do it in Ep9 if they wanted. Remember, in S3 they are likely going to introduce Edmure and the Tullys, and almost certainly introduce "Reek". Roose and some of the Freys will have already been introduced, which lets the writers spend all of Season 3 building up the Boltons, Freys, and Tullys.
In Storm of Swords, the Red Wedding is basically the culmination of their story arcs for that book. Even more so, when you consider that "Reeks" betrayal and taking of Winterfell is likely getting pushed back into S3. Juxtaposing Reek and the Red Wedding together in the same episode, or one in 9 and the other in 10, would be a great 1-2 punch and perfect ending to those story arcs that season.
As for Season 4, I do think it will end with most of the major things from the book. However, some storylines can extend further into Dance/Feast material and end there. Namely Jon's stuff.
- I think Joffrey dying will happen early in S4 obviously. In S2, we know Renly is dying in Ep4, which means the writers aren't afraid to do big death scenes early into a season. I think Joffrey dying in Ep3 or 4 would work perfect, and set up the rest of the Kings Landing stuff that season nicely.
- I think all of the Ironborn stuff from Feast will be moved up to S4, since its technically happening around the same time as the later events of Storm. Ending with the Kingsmoot or Vic leaving to capture Dany would be a good ending point.
- I think S3 will focus entirely on Astapor for Dany, while S4 will be all about her taking Mereen. Possibly even introducing some of the nobles like Hizdahr or Skahaz from Dance early to build them up for all the political Mereen shit that will likely be S5. I think Yunkai will be cut and the events there merged with Mereen.
- I think S3 will end with Ygritte dying and the main Battle at the Wall will be in the first half of S4, which lets Stannis get introduced earlier that season. I think they'll end S4 with Jon beheading Janos Slynt or letting the wildings through the Wall. That lets them move up 2-3 chapters from Dance to help fill out Season 4.
- I think Theon will be spend most of Season 3 holding Winterfell and interacting with Reek and Asha. I think the looming threat of Rodrick retaking Winterfell will be a big plotline that season for Theon, ultimately culminating with Rodricks death and Theon's capture by Reek.
Then early S4 stuff will be Theon in captivity, possibly showing his escape attempt and Kyra's (Maybe they'll use Ros for this lol) death. They can also move up a few Dance chapters and go up until Moat Cailin and end that plotline with Ramsay skinning all the Ironborn perhaps.
- Tyrion kills Tywin in Ep9 and in Ep10 he has a scene or two escaping on a boat, or already on the boat getting drunk, which would be part of Ch1 from Dance.
- Doing the Red Viper vs Mountain around Ep6 or 7 sounds about right. I do think they will hold off introducing Red Viper until early in S4 though.
- The Lysa Reveal and Moon Door stuff should be Ep10, with the Undead Cat reveal being the final scene of S4.
- Between moving up the Ironborn stuff from Feast and a few chapters from Dance, pushing back all of the Theon/Reek stuff to S3, and filling out the rest of the episodes with new scenes and possibly a flashback or two, they should be able to nicely do Storm of Swords into two seasons of 10 episodes.
Feast and DWD alone need to be 2 seasons that cross over with each other.
Feast and Dance can easily be done in 10 episodes. There isnt a single story arc in either book that couldnt be done in like 7-8 episodes. There are alot of POV's, but many of those only have 4 or less chapters each. A few with only 1 chapter if I remember. Plus, if you move up the Ironborn stuff from Feast and a handful of Dance chapters like I outlined above into S4, it gets alot easier.
If anything, I think you'll see a couple chapters from Winds moved up to S5 to give those story arcs a proper ending. I have a feeling that Winds will be long and very dense, and may need two seasons instead.