Golly!
I really feel for you folks who need the C-PAP. At only 70, I am still not needing one, and since I have a form of Lymphocytic Leukemia, I wonder if one is in my future when the disease starts really depleting my red blood cells till I can't get enough oxygen.
I do live in the desert, and usually camp in the desert as well. Last year on our trip to the north west, and North and South Dakota, Montana, Oregon, and Idaho,I did experience a couple bad nights at the altitudes over 9000 feet. So....I will have to get with my Hematologist, and find out!!