Hi Lynn, my growing area is different than yours so my Crassulas, Aeoniums, Haworthias and Echeverias are grown outdoors even when it rains here this winter. As long as our outdoors temps are staying mostly in the 30F at its lowest, they survive well, plus making the media very well draining by making sure all containers have pumice to aid in drainage. The critical time I do see real stress and damage is when it starts going in the mid to low 20F. I think as long as the plants have been prepared well prior to the onset of cold weather conditions, they get properly winter hardened and endures our mild winter conditions. It is a totally different scenario if the plant has been grown always indoors, bringing them out at this time will just just be a death sentence since they have not been acclimated gradually to the warm to cold conditions. and vice versa.
As to other tender succulents that I have to bring indoors during the winter season, some of them are Cotyledon tomentosa or Bear Paw succulent, Monoadenium ritchei, Senecio articulatus, Lithops, Schlumbergeras and most of my cacti which are at this time in dormancy mode.
