In reply to SambucaHughes:
I did it from the SE if I recall, and camped at La Siete Lagunas (spelling?). It was 30c+ in the valley, but -2c at camp. I had skimped on the gear and froze my nadgers off! Take at least a 3 season bag or a down jacket in a bivvy.
Loved it. Saw the best stars ever, zero light pollution.