Night King's plan
So prior to getting the dragon what was the Night King's plan to get past the wall? They were just marching up there doing nothing. Hardly seemed like a threat worth Jon Snow risking his life for.
shareWho knows, in the book, there's a magical horn that's said to be able to collapse the whole wall. I have no idea what TvShow NK plan were. Unless he was going to freeze the ocean like everyone first believed.
shareit turns out he didn't need any damn magic horn to bring down the Wall! In fact I suspect the rest of it will lose structural integrity, the magic that keeps the Wall intact has to be compromised.
shareIt's ice with a core of rock. Since it was built far enough north that it never gets much above freezing the rest of the wall should stand. Not that it matters. All the Night King needed was a gap big enough to march his army through. He must have had an original plan, but once he lucked out and got a dragon there was a quick and easy option.
The only way whitewalkers can reproduce is to turn infant humans, so they need a steady supply of them. Wiping out mankind would mean dooming themselves to extinction. I'm betting the Night King's true objective is to take the Iron Throne for himself. Humans would then be under his control, and every town and city in Westeros would have to pay a tribute in newborn babies for their king's generous protection (i.e. not being destroyed by the army of the dead). Since wights do rot and eventually fall apart the deceased would also be reserved for them. No more burials or cremations. Walkers would become the new nobility and all humans their subjects ... forever.
*shudders* That is a very creepy idea... but the best theory on the NK I've heard so far!
share"The only way whitewalkers can reproduce is to turn infant humans"
We don't know that, we know they CAN reproduce by turning infant humans, but we don't know that there are no other methods. We just know that we haven't seen anything else, and that as all the White Walkers seem to be male, more conventional methods do seem to be off the table.
We also know they're basically immortal, so once they've turned Westeros into New Antarctica with a beeeautiful ice cap over everything that used to be alive, they won't have to worry about reproduction.
We know the Night King is immortal, since he was in those cave paintings that were thousands of years old, and that he was the very first whitewalker. We don't know for sure that they're all immortal, or that there are no females (I've heard there are). Nor do we know if they'd actually be able to change the climate so it stays winter all the time. It's implied that if the Night King is killed all the other walkers and all wights will die. We can't be sure though.
I encountered a summary a few months back on the history of the walkers and their interaction with humans. Here's the post where I discuss it:
https://moviechat.org/tt0944947/Game-of-Thrones/59a3b107475c1d00118aac30/What-do-the-White-Walkers-want?reply=59a44322475c1d00118ab21d
If you've read the books, maybe you could comment on the accuracy of this material. It certainly hints that behind the scenes whitewalkers are more complicated than the silent and stoic beings we've seen so far. And that they can speak (assuming they have anything to say to us).