The problem with the Sansa/Arya twist is the scene where Sansa snuck into Arya's room. If they were conspiring together, there was no reason to have a confrontation behind closed doors with nobody else in the room.
Thought it was funny when Cersei called Jamie the stupidest Lannister. Although I think Tyrion is giving him a good run for the title. How many more times can his advice be wrong before Dany changes his position to court jester?
Cersei's plan won't work. Jamie was right, whoever wins in the North will march South and wipe her out. Her only shot was one of unity, especially if she stayed behind and Jon and Dany both died in the fight with the dead. She could have then taken the position, that I'm sorry they died defending us, but we lost a lot of good men as well. I did right by the kingdom, bend the knee. Her tactic will only serve to get her wiped out.
Of course it won't because this is a show and they're not going to let Cersei win in the end. The fans of the show would hate that. The Night King will be defeated. Theon and the Hound will get their redemption even if they end up dying doing it. Cersei will be defeated. Only question is how. My guess is Jamie dies valiantly in battle. Arya takes his face and kills Cersei. The only real question is what happens between Jon and Dany. I suspect that will be addressed by her becoming pregnant.
Unity and hoping Jon and Dany die in the fighting is not a plan for victory. If Jon and Dany die, the dead most likely would have won. Letting your two enemies fight each other while you build up your forces is a good plan.
Cersei correctly surmised that one of the dragons is dead. If one dragon can die so can the others. Without the dragons, Jon and Dany's forces are very beatable. There were only 8000 Unsullied to start and at least 1000 should already be dead from fighting. Robb Stark's northern army only had 20K men and they were pretty much wiped out. The Dothraki are impressive but they aren't made for conducting sieges. If Jon and Dany defeat the dead, their forces will be significantly depleted.
Meanwhile Cersei is rebuilding her forces. 20k Gold Company mercenaries are on the way. Euron controls the seas. More ballista can be made. More wildfire can be produced. The way Qyburn was looking at the dead remains, I wouldn't be surprised if Cersei has her own dead (or half-dead) army.
They can't defeat the Night King without the dragons. Thus at least 1 dragon will survive the fighting. Cersei also just isn't likeable. The people won't be on her side, which will eventually lead to her downfall. You can't keep power for long if no one wants you to. She is taking a position that will lead to the other side being the one the people back (unless it is the army of the dead). If they see any crack in the shield, they will bolt to Jon/Dany, especially as the whispers of Cersei's betrayal become louder and louder.
Obviously at least one dragon will survive since it is a TV show but that is not a given. Valyrian steel and dragon glass kill white walkers. The dragons are needed for mass destruction of the dead. Of course, wildfire would work quite well against them too. As for the dragon, just need a bunch of the ballista.
What world do you live in? Brutal tyrants keep power quite well. Now and throughout human history. The people generally don't matter. It is the important power brokers that do. Hence her move to get the Iron Bank on her side. Cersei may not be liked but she's been an efficient and steady ruler. She's not oppressing the people. They are free to go about their daily lives. She's also a southerner.
Why would southerners flock to Jon and Dany? If I'm a southerner, I'm quite happy not to be sent north to fight and die. Jon is a northerner and Dany is a foreigner and they are both Targaryens. There is no desire to be ruled by Targaryens again after the Mad King. Refer to how the threat of Dany, the Unsullied and Dothraki was used to turn the Tarlys against the Tyrells who they were pledged to.
Even with the Golden Company, Cersei doesn't have the army to control the south, let alone the north once that army marches back down south. Remember the Golden Company is 20,000 troops, but a million people live in Kings Landing alone. She can't keep the peace without the support of the other great houses (or whatever is left of them) and she absolutely needs the resources of High Garden, Dorne, etc. to survive and pay back the Iron Bank, but she doesn't have the forces to keep those lands without the support of those people and their lords, and she won't get it because she is a tyrant. Tyrants keep power when they have the military force to keep power, Cersei quite simply doesn't have that and she never will. It is only a matter of time for her. Her treachery might buy her a bit more time, but the end game is the same, and not just because this a fantasy, because Martin could easily end this series with a tyrant on the throne, it is just that Cersei isn't the right tyrant. Frankly, I wouldn't be overly surprised if there is a tyrant on the thrown at the end. I just think it would be far more like to be Dany, as I can totally see her going full on villain. She has that cold viciousness that Cersei does and she could easily be triggered into a downward spiral (you know if her dragons die, Jon, Jorah, Tyrion, etc. all die as well). She will still defeat Cersei though because she will be much better positioned to do so with the better trained forces and the full support of the north if she leads the defeat of the Night King (she also would more than likely have the 3 Eyed Raven on her side). That said, I believe Dany dies and Jon ends up on the thrown after he defeats Cersei. As this has always been his story and that of his "siblings". Everyone else is just filler to get the story to the end point.
Is Bran and the Night King somehow intertwined?
It wouldn't surprise me if Tyrion gave Cersei the idea to deceive everyone, as we know he will do anything to save his own life, and him watching Jon go into Dany's room showed us some sort of resentment/regret. Cersei was also very quick to say Jaime is the stupidest Lannister, possibly hinting that Tyrion had an idea she approved of.
Speaking of which, I read a theory that Tyrion isn't actually a Lannister, hence why Tywin had repeatedly stated he wasn't his son. He also looks nothing like them (blonde hair, blue eyes). The theory surmised he is also a Targaryen.
Gendry must have some sort of importance to be brought back this late. As the **** Baratheon, he has no claim, right? So how's he going to impact the show? Besides being the fastest runner, of course.
All in all, there were a lot of cool scenes season, but the storytelling definitely suffered from the condensed season. For every jaw-dropping scene, there was a scene that deserved a roll of the eyes.