Agree with Hetty, especially if your plants have really been indoors all this winter and are still very young. My succulents stay outdoors so they can ably tolerate the swings in temps. From what I have, Crassulas like jade plant, capitella campfire, they have endured up to low 28F as long as they are not too wet. The succulent euphorbias I have, are struggling, actually the candelabra died early on during the early onset of Fall rains. I was surprised with my Epi newport, it has survived its first winter outdoors very well. Winter this year is really drier too, so it could be a factor. I also notice if the succulent have not developed that bark like texture on its stems, it will have low tolerance to cold. So younger succulents really have tough time during winter and eventually die.
The only succulents that I have kept indoors all winter long, desert rose, sansevieria, lithops, split rock, and plumeria.
