Something about a bird in the hand and one in the bush. Things maybe looking good for Tyrion in the future but he was last seen jousting on a dog trying not to catch sea aids. Not so great. Dont really know how Dany will feel about adding a kinslayer and kingslayer to her crew. She is a bit paranoid about being betrayed these days.
You should reread dance then because the last time we saw Tyrion he had just wheeled and dealed his way out slavery while also cinching the allegiance of the second sons in the process.
As far as a Northern alliance goes I ask you this. What North? The north is battered broken and bloody already. What will be left once Stannis and the Boltons play out their feud? But if you absolutely need a northern tie how about a certain Ser Jorah Mormont? One of the last living knights of the north and the last living son to the once proud house Mormont. Until a Stark returns to winterfell there is no north. And even when a stark returns do you honestly think they side with Littlefinger? The man who betrayed Ned Stark and left him short by head?
Now sure Sansa's part in this story will give that line of thinking some pause but we've already seen her become more savvy in the ways of the world. She is better suited to play this game of thrones than any of the Starks and she is learning under one of the top three. It is only a matter of time before she figures out littlefinger is a lie (that's if she hasn't already done so). So she is a far cry from something solid for littlefinger to stand on.
Tyrion has a tie in with literally every major power on the board right now and they all like him (or have a reason to like him in the future)..... Minus Cersei of course.