Sunwell Soloing and I: How to skip Madrigosa's ice wall

If you're a transmog junkie like I am, you may find yourself doing old content a lot. I've been running Sunwell lately for various pieces of the DPS plate set that dropped here, and one of the things I got really tired of was the big ice wall that Madrigosa puts up just before the Brutallus encounter. First off, it's not impossible to see through it, but it does kind of obscure the action. Secondly, I'm just cantankerous and contrary and I don't like it when some dragon from three expansions ago tells me where I can and can't go. Today, however, I discovered that I don't have to let her make that decision for me -- it's possible in fact to completely avoid the ice wall and drop down into the Brutallus area before she casts it.