I am starting to feel like I am having a bit of success with Den. cuthbertsonii (at least alive, growing and blooming for a couple of years) so just maybe I am finally learning to grow this tricky species... My summers are a little on the warm side for them (daytime summer highs mostly below 85 deg F, 30 deg. C, occasionally a bit higher) but relatively cool summer nights, that seems to help them tolerate the heat. Winter lows mostly above 40 deg F, 4 deg C, occasionally a bit lower but little or no frost. If medium is well-drained (or even better, mounted) rain should be no problem. Pure water is critical (until I got a reverse-osmosis system, I failed miserably with them), rain is of course the best. They can tolerate quite a bit of light - I had been growing mine fairly shady, then talked to Andy Phillips of
Andy's Orchids, who has a huge species nursery in my area, and he has found that his Den. cutherbersonii bloomed much better with more light. So, I think dappled sun or bright shade.
But unless you have significant frost, outside is definitely the place to grow them. If it is only for a few hours, a bit of frost won't hurt them. This is definitely a cool-growing species, summer heat is more of an issue.