I did that 11 years ago up there.  Spent the worst night of my life in a snow hole, ill prepared for it, and came to with the whole-body-barfies in the morning about when the sun tried to thaw me out.  Was so cold and cramped from shivering all night, I couldn't swallow down any of my ice chunky water.  
  
Now I always cary a space blanket, extra wool top and bottoms, and goretex overmits now.  Doesn't take up much space in the pack.