Terrible episode. Completely unrealistic. From make believe creatures like giants and wooly mammoths attacking a 700 foot wall of ice, to Jon Snow's pitiful bastard sword technique. GRRM just needs to learn more about physics before he tries to write any more fantasy novels. I demand nothing less.
I think I'm going to give up on this mess, and go back to watching shows that are actually grounded in reality like Trailer Park Boys.