Thijs, although my DR plants are indoors for the winter, the light level is not very high, and we seem to be having a lot more than usual cloudy days this winter. So, like most succulents, I thought that it should be kept drier during this time, especially since growth will be minimal. I thought that they were going dormant, as the plants dropped lots of leaves in response to the lower light levels.
I need to find a way to set up some supplemental light for plants indoors during the winter. I have lights in the garage, but it too cold for DRs.