Think this is my greenhouse or potting shed?
No! My potting shed is full; all surfaces filled with tender succulents and citrus. It stays well above freezing in there. A west facing window gives plenty of winter sun to cactus and succulents.
My greenhouse? Filled with the more hardy plants, that can withstand cold temperatures but not freezing. It warms up during the day and the thermal mass of water-filled bottles and plants usually keeps the temperature well above freezing.
It's my laundry room. It's the place where I keep my orchids during their non flowering season. They can't withstand too much cold so 65º is just about right for them. Throw them away after they finish flowering? Never. Also, I have to have a warmer place to keep seeds while they dry out. These are Cascadia peas which have been prolific right through until this last week.
and these bunny ear cactus pads I discovered on the ground yesterday.
I left them to dry overnight in the greenhouse but today I noticed the base of the pads were showing signs of rot. We have had so much rain this fall and coupled with cold it has not been good for the succulents. But, I know they can be saved so I took a knife and cut off the bases down to good tissue. It's rather like being a dermatologist going deeper and deeper making sure he remove all the cancerous tissue. I had to makes several cuts before I was down to healthy tissue. Now they will stay in the laundry room until they callous over after which time I will pot them up in a well drained soil.
Cactus and succulents can be so forgiving if you remove all the unhealthy tissue, heal and replant. I have done the same with a sharkskin agave and a Spanish bayonet yucca. The center of the sharkskin just pulled right out but I replanted and it is growing again. The yucca had been attacked by weevils but I cut back to good tissue an replanted.