sounds overambitious to me.

You haven't toured carrying your own stuff before, you'll be over 10,000 feet all the time, and you'll be in a different culture/country.
I realize that this is a plan for a year away, but what's the story with a three day ride? Will you be there for a planned work event or something?

easy answer to your question is that you will need to get lots of riding experience with a touring load before this trip to see yourself how it goes for you, not to mention experience with what things to buy, how to pack. Depending on where you live, still might not address the high altitude thing.
Altitude sickness can be weird, one person can be fine, and another really fit young guy can be seriously affected.