For those who may not know, a three act structure is a general story frame that denotes points in the story where dramatic tension rises, climaxes and then falls.
There's a fancier way of describing it, but from my understanding, each act bookmarks phases of the story. Act 1 establishes the setting, characters and starts the story; Act 2 raises the stakes in the story through dramatic developments and twists that place obstacles in the way of the character's actions and beliefs; and Act 3 is where the plot begins to resolve itself with all of the threads winding together into a conclusion.
Seeing as that ASOIAF has seven entries and always seems to have something happen that keeps things tense, how can we judge where we are in the Three Act Structure? Obviously AGOT belongs in Act 1 because it's the first installment that introduces the characters, mood and tone of the series and ASOS belongs in Act 2 for having some of the most infamous events/developments in the series yet (Red and Purple Weddings; Revelation that Baelish poisoned Jon Arryn and started the whole plot; Jon Snow becomes Lord-Commander; Jamie becomes a likable character; Tyrion kills Tywin and etc.).
But where would the rest of the books fit into the three act structure? Or is it a situation where Act 2 will stretch out until Book 7 with Book 1 being alone in Act 1 with all of the other books in Act 2? Is the Three Act Structure even applicable to ASOIAF?
I'm also asking in consideration to what appear to be the primary three plot-lines around which the characters and story most heavily revolve around: Winter coming to the Wall; The Game of Thrones and connected War of Kings; and Danaerys in the East. We'll never get to Act 3 until all of these major plot points reach some sort of huge game-changing climax that puts everything in the past books into perspective on how they're connected and how these events of dark and tragic events led to the only possible resolution to the crisis if there is one.
For example: Let's say that Danaerys comes to Westeros, kills (F)Aegon and absorbs his faction and then conquers the weakened Seven Kingdoms. That's two major plot-points that have come to climax and resolution. But this is done while ignoring the third plot point involving the coming of the White Walkers, then that's a loose end that could undo anything that Danaerys has gained and the story won't come to a true resolution until it's dealt with. Maybe by having Dany use her new power and her dragons to come to the aid of Jon and the Watch and defeat the White Walkers through a Song of Ice and Fire that the bards will sing of for ages.
Maybe Jon and/or Dany won't live to hear the songs, but at least the realms are safe. At least all three plot-threads have come to some sort of satisfactory end that ties up all of the loose ends with surviving characters using the newfound peace to rebuild the realms and heal their grievous emotional and/or physical wounds.
Here's another one.
Let's say that both R+L=J (I believe it's a valid and well evidenced theory, but remains a theory until absolutely confirmed by Martin) and the GNC are true with Jon Snow defeating the white walkers as AA and becoming King in the North while becoming de-facto Ruler of the other realms after the Lannisters, Tyrells, and Martells destroy themselves in their game of thrones and in the fighting against (F)Aegon. But Dany is still in Eastos...and since Martin himself seems firm on 7 books, it would be a bit of a cop out for him to keep Dany in Eastos after all of the build-up for her to come to Westeros and fight to reclaim her birthright.
My point is that I just don't see where the resolution for all three plot-lines will come from. I can see possible resolution scenarios, but they all involve leaving out one of the essential plotlines and that's a huge loose-end that shouldn't be ignored at least according to the Three Act Structure. That would something of a cliff-hanger and those don't do so well unless there is a clear intent for a sequel which Martin has made clear he wouldn't do.
So back to the original question, where are we in the Three Act Structure if one is applicable and when will we able to mark where the resolution involved with Act 3 begins?