What should be done with the Riverlands and the Westerlands?

Harry is poised to invade Lannisport and, once again, is in a position to bring down Casterly Rock. This time, Tyrion Lannister is the lord of Casterly Rock, not Tywin.

At the same time, the Riverlands and the Westerlands have pretty much rebelled against the Iron Throne's authority. But Stannis can no longer impose his authority in those two kingdoms as Aegon, backed by Dorne, is attacking him from the south, and Daenerys, backed by Euron Greyjoy, is attacking from the east. The Vale has isolated itself after Jon Arryn's death, and the Reach is divided on who to support.