As much as we enjoyed watching Drogon nuke hundreds of the Lannister soldiers, I'd like to hearken back to the previous episode, if I may:
You will recall, I'm sure....Archmaester Ebrose reprimanded Tarly for disobeying his direct order to forget treating Jorah Mormont's greyscale...while praising him at the same time for his compassion, intelligence (and no doubt, courage...Ebrose recognized it would take great fortitude to attempt such a procedure even for the most seasoned of the Citadel's maesters).
His reward was to begin transcribing a rather large tableful of what appeared to be stacks and stacks of very old manuscripts. Not an original thought here by any means (and prolly somewhat obvious, right)....but no doubt Ebrose (who has already acknowledged that he believes Sam's accounts of the Whitewalkers and the Army of the Dead) is handing Sam pertinent (and I suspect "classified") information contained within those very same ancient parchments.
The info could be as simple as
Get Yourself Three Dragons from the Hot Blonde in the South and Nuke the Bastards Back to Hell, right? Or maybe there'll be some kinda ancient incantations that'll raise the Children of the Forest back to life to team up with The Living and help defeat the Night's King once again...I dunno.
Right now things look somewhat daunting unless The Living get a decided edge other than depending on the Dothraki army and/or the 8,000 Unsullied. When you're facing a potential army of tens...hundreds?...of thousands of the dead, some kinda magic (other than Dragon Glass) just might be the ticket to victory (and survival).
This much we know....lotsa people (and ones we like) are still gonna die. That's how GoT rolls.
Looking ahead.....wouldn't it just piss everyone off come the end of this series, we wind up with the Crusader of Chaos, Lord Baelish sitting on the Iron Throne after all? And why not...? Isn't he, himself, diabolical enuff to cut a deal on the side even with the ice-cold Night's King, hmmmm?