My Cactus lost this Winter

[NJGardenGuy]

I grow all of my Cactus in pots. They spent last Summer outdoors. In October I brought them all inside the house to spend their winter dormancy period. I had each Cactus cataloged with a brief summary of cultivation requirements. Most if not all of them stated to keep the plants Dry in Winter (this information was obtained from the Cactus encyclopedia). Unfortunately, as the winter progressed I began to see cactus collapsing in their pots and dying. At the time I was growing a wide array of genera: Maxillaria, Parodia, Gymnocalycium, Echinocereus, Echinopsis species and hybrids and various others. By the end of winter I had lost over 20 cactus.
I am wondering if the lack of water of the course of the Winter had anything to do with this. Was my house to warm? Did they not get enough light? Perhaps someone can help me understand this......

[Aiko]

Totally dry for months is not a killer for these plants. I also keep my plants in an unheated dark room for about four months during the winter. I hardly lose plants. Maybe it was too warm for them. How warm did it get regularly? My plants are at about 10C for most of the time, even if I have a small window slightly open for some fresh freezing air (the room is one floor up).

[ElieEstephane]

If they collapsed i'm guessing they rotted. Dry cacti would just shrivel. If they indeed rotted, it could be high humidity and/or lack of air circulation. Did you check for pests? What soil do you use?
I keep my cacti at the same temps as aiko and sometimes even higher on a sunny balcony and on a shaded balcony. They stay bone dry all winter and i only water the ones that shrivel too much and some succulents.

[adetheproducer]

What soil are you using? Could you add a couple of pictures?

[TimN]

In my experience only tiny plants or seedings will die without water for extended periods. I agree that a collapsed cactus is more likely something other than lack of water. That said I do lose a plant or two over the winter. My plants stay outdoors all year, though. I also water my plants year round. Less frequently in the winter, but I do water.