Nomad, cold weather is not a concern. The Tesoro winter is mild compare to Canadian winters. The only concern is travel to and from the site during the rainy season, from May to Dec. Here is the excerpt from the Paul Gray report:
4.2 CLIMATE
The climate of the Tesoro Property is typical of the high mountainous desert regions of southwest Peru, with hot dry days and cool evening, summers tend to be warm and winters cold. Annual temperatures range from 10° C to 32° C. Year round development and mining is possible, however field exploration seasons are best conducted from May through December as during the rainy season, the Acari River ford at Otapara is impassable and alternative access required. A well planned program can run well year round on the Tesoro Project however.
No weather stations are available for the Tesoso Project, however during the xploration life of the Project by St. Elias (5 years), no appreciable rainfall whatsoever has been reported. Anecdotally, Otapara locals indicate that no rain has fallen on the Property or area for more than 25 years.