They don't actually thrive at 50 but they will be ok. I would say that 65-72 is absolute optimal temps and if you can control the temp of the room they are in that is much better than trying to maintain viv temps.

Good to hear they are out. They usually come around. The stress of being moved is all it takes to send them running and hiding for a while. Even trimming back the plants in their viv will cause this.

Michael