I feel like i just had the best idea they could have had for ending Game of Thrones. Hear me out
Arya arrives in Winterfell and hears about the Night King and the White Walkers. While she did likely cause some issues for herself with the Faceless Men, she didn't like, kill all of them, and if they really didn't like what she had done they could have kept sending Faceless Men after her, but they didn't (At least as far as we know by the end of the series). Sure, it could be that they didn't care to or any number of other reasons, but it is still important that they didn't (Additionally, they might not be able to as they cannot choose who to kill themselves and thus maybe wouldn't have killed Arya unless given her name by someone else, and since it appears the Waif and Jaqen H'ghar also largely broke the rules with her they may have considered it a wash overall)
Either way,what Arya did was not likely even largely known outside of the Faceless Men, but it appears that most/all of Bravvos worship the Many Faced God AKA death. They say that "All me must die" and that "All men must serve." Well, the Night King and the White Walkers likely would have been considered an abomination to anyone who followed the practices taught at the House of Black and White. They would want to kill them because they would harm the world and would be an affront to the god of death. The Faceless Men are some of the most skilled killers in the world and Bravvosi fighters in general seemed to have some skills. There are also a fair number of people in Essos in general who likely follow the Many Faced God, and likely could have been recruited to help. Contacting Bravvos about the issue would likely get the ball rolling on this, which could have been done by raven
This would have likely resulted in fewer deaths overall and would have have likely sped up that battle in a way that would have allowed for more actual content and not just long battle scenes where much wasn't happening
Following that, they likely would have left, but they likely would have given Daenerys a warning or their presence would have been warning enough that reaping death and destruction against the innocent was a good and quick way for her name to be given to the Many Faced God
With less of her army eliminated, Cersei wouldn't have likely felt confident enough that they would win. Maybe she still would have tried shit, since it is Cersei, but even if she did, Daenerys likely would have had a better response since she didn't just lose a bunch of people and likely would have been more confident in their success without causing so much destruction, while also keenly aware that a Faceless Man could be told to kill her if she did. Either way, she then could have taken the throne without so much bloodshed
At that point, she could then announce who Jon was and his history, and Jon could have abdicated his right to the throne. He didn't want to lead the Seven Kingdoms, he didn't even want to rule the North, he would be fine to do this and the people would likely accept it overall (Those who didn't likely would struggle to find a toehold since he didn't want it) He could also abdicate to Sansa (Bran too since he wouldn't have wanted it) and for their role in her victory, the North could be allowed independence with the stipulation that the countries remain friendly
From there, Jon could have gone with Arya (and Gendry, who should have been on that ship!) To explore the world. He could have easily acted as a driving force for them to return home every so often as well so that the Starks could be reunited once more
Bran could have been Sansa's advisor and the memory of the people, so he could pass on the knowledge of the past to the future generations
The people Daenerys brought with her who survived would all have their own roles to play of course and many would likely be permitted to go live their lives however they should choose. She could choose to remarry or she could choose to adopt a child, grant them her name, and make them her heir. From there it would be all about Westeros settling into their new normal, fixing what had been broken, and crafting the future they desired
This would have been better overall in my opinion
