Saw this just last night. I spent the rest of my night trying to figure out WHAT THE **** to do to escape, if possible. The best idea I could come up with is quick attacking OVER the trajectory of the ice, and risking an awkward landing on the stage near the edge.
That way, when you land, you aren't in "Help, I've fallen and can't get up!" mode, so the ice doesn't lock you. Depending on your spacing, you my not even get damaged for that matter. (If you look at Pikachu's damage closely in the video, there's a point where the Ice blocks only make him flinch and don't damage him)