5. Remember Rickon?
You may have forgotten about Rickon, the youngest Stark, because he’s been missing from the show for two full seasons. However, in the books there are hints he is coming back soon, which means it is likely he will also reappear on the show.
In A Dance with Dragons, Ser Davos is sent to White Harbor by Stannis in an attempt to win allies. He is basically tasked with a side assignment to find Rickon Stark on the Island of Skagos, where he is rumored to be hiding with Osha. Since Stannis is dead this won’t play out the same way, but if Davos joined team Stark in support of Jon, Jon might ask Davos to find Rickon for him.
On the show they could age Rickon up since so much time has passed and he could become a more important player in the Game of Thrones. But since Martin abandoned his planned time jump to take place between A Storm of Swords and A Feast for Crows, Rickon probably won’t do much in the books.