I don't think there's necessarily a happy ending coming either. I could see Sansa surviving as Lady of Winterfell. I'm not sure about Arya. I think Bran survives as the Raven. Jamie dies, I think. (But I want a great, heroic death for Jamie!) Cersei definitely dies. I don't know about Tyrion. I like the idea of Jorah becoming the next Night Watch.
I recently watched a 16 minute Youtube video about why Rhaegar Targaryn is the real hero of the series that brought up a lot of interesting points.
I think Jon Snow is Azar Ahai, & he gets Lightbringer (the sword) from Dany's death.
Was it season 2 where Dany had that the weird vision-dream sequence where she was in some wintry place & then exited there & then entered a tent where Khal Drago & their son were waiting for her? So I think Dany dies... possibly Jon ends up killing her, but I could see her dying in some other way as well. However, w/ her death, Jon gets Lightbringer.
I'm not sure about Jon & what happens to him.
Game of Thrones is the "Song of Ice & Fire," & that's what Jon is - the son of Ice (Lyanna Stark) & fire (Rhaegar Targaryen).
All along, this has been Jon Snow's story &, to a lesser extent, Dany's story, &, to lesser extent, Tyrion's story - they're the 3-headed dragon.
I do think Dany is pregnant w/ Jon's baby, & their child is the true Song of Ice & Fire & the true heir to the throne - and the person to whom Sam is telling the story.
Jon Snow is the promised prince. Dany is his lightbringer. And their child is the heir to the Iron Throne.
And I would love to see Ser Davos becoming the Hand of the King to Jon & Dany's child - although he'd have to live a very long life.