Having the right gear for the job was definitely an advantage though. My OMM jirishanca swallowed all the flags, the boxes, my warm gear (which was most certainly a necessity after nearly getting hypothermia on one foray) AND the stakes, with ease.
No, really. Good luck.
The ground is really soggy up there. Although there was a bit of snow and ice, it hasn't frozen solid enough to stop you from going through it and right into the bog beneath. Big grippy shoes will be the order of the day, waterproof socks, and decent windproof layers.
The air temperature wasn't all that bad, but the wind was really really cutting. What with the ground underfoot not being entirely conducive to fast running, I probably wouldn't rely on speed and effort to keep warm. In fact, the fact that it'll be slow going underfoot, and you'll be potentially spending time pacing out from features to get controls, I'd suggest running hotter, rather than colder, BIG gloves, waterproof/warm socks, and a shed load of food. Oh, and a torch bright enough to make me think that the sun is coming up when I look at the hill from the house. (with spare batteries).
Just to give you an idea, I very nearly became hypothermic within sight of Snake Summit from hail/snow/windchill yesterday morning, so please don't skimp on gear.
Whatever happens, its going to be a fun night. I'm praying for horrendous clag, but that's just coz I'm mean.