I am planning a trip to South America at the end of Nov through Dec.  We will be on a few routes in Ecuador and then heading to Argentina to attempt to Aconcagua.  Im trying to figure out the boot situation.  Right now, the warmest boots I own, and  love, are the La Sportiva Nepal EVOs.  Ive seen recommendations for plastic double boots, but, who really wears plastic anymore?  Im curious if anyone can recommend a tried and true method of ramping up the cold weather rating on the EVOs…super gaitors? Overboots?  Am I crazy to think I can get away with the Nepals?  
  
Any and all feedback is welcome! Thanks!