The Starks will rule the iron throne/Westeros at the end. Westeros breeded their own downfall with the starks and they don't even know it.
John is going to go on to be a noble respected warrior who will be on the throne. He's honest, there are no lies when he talks, he can fight, and there is nothing he would tell his men to do that he wouldn't do himself. MEN will realize that and he will be respected by MEN. You can already see the seeds of it growing. The sneaky people with a lot of money in the story won't understand cause just like sneaky people with a lot of money in real life don't understand that having all of that doesn't make you not a lame. You're so cunning and conniving and have all these possessions but don't realize it can't buy you real respect. Sometimes you just gotta be dat N***a.
Arya is going to be a legend/myth in the world with her warrior skills. She's going to be John's number 1 goon. She won't be up under him all the time in the castle, she'll be out doing her own thing but she won't tolerate anyone messing with her family. So if you don't want those problems from her then you best not try John in the first place.
Sansa, like I said before Sansa is the next Cersai, Cersai 2.0. Everything she's going through is going to turn her into a cold, twisted, ***** of a woman. Everybody think they're using her as a pawn and taking advantage of her (which they are) but not realizing that if she lives to grow old then all it will be is learning experiences for her. She will learn how to deal with people like them and become people like them or even worse version.
Bran is going to be some kind of mystic and people all over will look to him for knowledge.
Rickon can handle the family money or something idk.