Just gut instinct on Sansa. The showrunners seem to love the actress and her character, an opinion I don't share. They've also treated LF's "grooming" of Sansa as an exercise in proper rule instead of the cynical nihilism that I think it is.

The books are much more ambiguous about Sansa, but even there you can find hints that she's a potential candidate. The biggest one is that her character is modeled on Elizabeth I.