Let´s work with what we know:
- George RR Martin said in his last interview that the ending is gonna be bitter-sweet.
- The author doesnt believe in happy sweet endings, he like to keep things real.
- Its safe to say we will not going to have a happy ending and fans need to start to accustom with this idea.
I dont believe Westeros is ever going to have peace, because the author showed us that the world will always have bad and good people with their own agendas. And showeds us a lot of old wars in the Westeros history. Its irreal to think jon and dany will bring peace to Westeros. The world dont work like that.
My ending theory is a end going full circle similar to what we already saw:
- Years will pass, Sam is going to be narrator in the last scene for a younger sam.
- People will say to children the targaryens and dragons ceased to exist ( jon dragons and dany will die)
- a baby from a forbbidden lineage/ love story will be born and Tyrion and Varys will hide him from the world
- someone will discover new dragon eggs
- the iron throne 1 - will be destroyed 2 - the most least expected person will seat on
- a family from a proeminent family will be apart restarting the beggining of a new adventure.