I used to live at 8,500 feet and was adversely affected. I needed to wear oxygen 24/7. Now I live at 800 feet and don't need oxygen at all- even when exercising. >10,000 is exponentially worse than 8,500. Before you go, you should have a High Altitude Simulation test to see how you'll do. If you're not on oxygen, you might need it. If you are, you'll likely need more. It will be important to monitor your oxygenation either way because you'll be at altitude longer than the test will run. When mine was done they put in an arterial line (like an IV but in an artery), to draw blood gases which is the most accurate test of oxygen saturation. They also had me exercise- probably to make up for the fact that the test doesn't go on for the hours you'd be at altitude. I can sustain my O2 level now for about an hour and a half at altitude, (in an airplane for example) then it drops. Your heart has to compensate for the lower availability of oxygen and it may not be able to keep up. That depends on how good your heart is of course. Good luck!

High elevations can trigger worsening symptoms. It would be best to talk with your doctor about travel to such a high elevation before attempting it. Machu Picchu is on my bucket list too. However, I don't do well in elevations that are much lower. 5000 ft. seems to be the max I can tolerate without experiencing extreme shortness of breath and chest pain.

Portable oxygen with you for sure. Talk with your PH specialist. I took a camping trip in spring, our spot is at 3200ft elevation. I had no portable oxygen and got real sick. So my specialist ordered a high elevation test (have not done yet) and a desaturation test (which I failed gloriously and am waiting on portable oxygen). Perhaps these same tests could help you know what you need for your trip!