If we can't talk about one of the evidences, how can we talk about any of them.
If ice walls somehow indicate an unreachable land of unknown size, then we must have many of those around the world--the unreachable lands, that is. But if one can go a few miles or even a few hundred miles, if necessary, to go around them, as shown from the pictures of Antarctica, then they aren't the mystery-hiders your sources seem to think.
Ice walls by themselves are no such thing, as Knight pointed out--there are walls of ice in the grocery store. If you are willing to admit that your ice wall evidence is no longer evidence for a flat earth, then I'm more than happy to stop discussing them. We can move on to something else, like the Great Circle distances I mentioned before,
here.
If you still believe in the ice walls, you need to present some evidence that your evidence is true, and that it indeed is useful in determining the shape of the earth, as you claim. That's what this thread is all about, isn't it?