Predictions for tomorrow?
It's really hard to predict this one. It really looks like the "good guys" are totally screwed, yet it still feels too early for many of them to die. There's just so much unfinished business with many of them.
The only characters that truly feel expendable are Tormund, Podrick, Greyworm and Missandei. Brienne too I guess, but it feels too obvious after the last episode. Beric also feels like an obvious choice to die, not being a big main character, but he still needs to fulfill whatever purpose he is destined for, which is probably tied in with The Hound and Melisandre, who is not around yet, which makes me think he'll make it out of this one.
Maybe Theon will die protecting Bran and Sansa. It kind of feels too soon for him to go, especially with Euron still alive, but I can definitely see him being the major death of the episode.
I reckon the dead will start rising in the crypts and Tyrion will be the hero there by saving everyone via a secret escape route or something. We may even see a wight of Ned Stark's skeleton.
If everyone's retreating south after they lose the battle, the Night King would easily be able to chase after them on his dragon and burn(?)/freeze them all, unless of course one of Danaery's dragons will sacrifice itself fighting Viserion, giving everyone enough time to make their escape.