I did my training in South Africa in Johannesburg... 5270ft alt and temps ranging from 0 to 35 degrees C from winter to summer. I now train students in similar circumstances.
For me it was the place to be trained and for training...
If you learn to fly at alt going to sea level is a gift.
Here we always have to keep an eye on limits as our DA is always high - mostly running with limited fuel for sorties of an hour or so. Teaching students to fly a R22 on limited power at altitude makes for a better, more cautious pilot. Even if we have students wanting to learn on a R44 or bigger, we start them on the R22, just sothat they learn flying with limitations.