Okay...let's say that Winterfell is attacked as a diversion, while the NK heads south towards KL. Which means that if the good guys actually win at Winterfell, that may still be a strategic loss if it prevents those forces from joining the real battle at/near KL.
So I'm thinking two big battles. The first is the Battle of Winterfell, which ultimately is a diversion for the NK to slip past them and head towards KL where there are fewer forces to fight him. The second is when/if the victorious defenders of Winterfell realize they've been "had" and race south. We know from Tormund last night that riders are faster than the NK's army, so the Dothraki might race down the Kingsroad to catch up to the NK's army. Ground forces could go to White Harbor, or maybe get lifted by Yara's fleet south to the Riverlands, and march the rest of the way. So we see a big battle down there with all major participants in proximity.
I guess that would work.
I still see the Isle of Faces as being important, though. i know the show has barely mentioned the God's Eye, but all it would take is for Bran to explain why it is important to plug that hole.