That sounds pretty good. Temperatures are nice and moderate. They will appreciate the high light. I would personally try growing it outside if you get a good sized ceph. Don't worry about humidity. I used to grow my cephs in a room with 30-40% humidity in a media with orchid bark 40%, perlite 20% and peat 40%. If anything, have a tray with some pebbles and water to place the pot on. That should make a nice microenvironment. But, if you are going to place it outside, it might need regular and constant watering in this media. Cephs don't mind this treatment at all.