You're likely to encounter some strong contrasts with fairly bluish shadows under open skies at higher elevations. I would strongly recommend carrying a couple of light balancing filters. I personally
use an 81A for general overcast, and an 81C for shots in deep blue shade. Don't count on the film
itself to automatically correct for this. That would be a myth. Things like polarizers are unrelated,
and are more a creative option. Skylight filters are a more complicated question, and can help with
UV sensitivity affecting sharpness over distance at high altitude. My experience with this is mainly
with Portra 160VC, which is probably similar to the current films; and in this case I had the best
results with a light pinkish-amber Singh-Ray "KN" UV filter.