D. villosa looks a bit like D. capensis.
I don't know what their upper heat tolerence is, but as long as they get a good temperature drop at night I think they are happy. I wouldn't expose them to temperatures below the high 40sF either. I'll run some tests with some of my clones since I have plenty (until I give or trade them away).
My D. roraimae flowers would always abort. I don't know what they want to be happy. Doesn't matter since the plants croaked.