Think of it like this, the “ice wall” is there because the sun can not travel beyond its set trajectory to melt it. So the ice plain could be infinite just like space.

But what if there are other suns along this ice plain, other “planets” with their own sun on the same plain a few thousand miles away. The FE map could just be one tiny little pin hole in much larger world.

They want you to believe you're just a cosmic piece of dust and insignificant. A random chance, a coincidence.