Hi niknac, just put it back in a very well draining soil and wait. Place in a part shade area. Depending on how warm it is already in your area, it should bounce back. Typically, haws, do not like being too cold or in too direct heat. But they bounce back very well.
I see a lot of green still remaining in your plant, so there is still lots of hope. Give it time. At times, the plant will naturally seem to go on a dormant mode, not growing anything as it experiences extremes in conditions. But it will recover, in a very, very slow pace. I would not water it now, since there are no roots. Just wait, to me it looks the greener leaves are still firm, so it has enough moisture to sustain it.
It is such a slow growing beautiful succulent, so patience and maximum restraint in watering. You will know it is starting to grow roots if you slightly tug the plant later and there is resistance. New leaf growth will come from the center.
Just to add, the plant is happy with temps in the mid to high 70's to mid 80's. In winter, if you say it was not doing anything for 2 to 3 months, it is just like that, on rest mode not happy with the temps or the amount of light, so most succulents, will drop leaves to only maintain what it can sustain in such unfavorable conditions, and will resume active growth, once conditions are better again. That is often the time people accidentally kill succulents, thinking it is withering, it needs water. It is actually the reverse, have to really pay attention to the ambient temperature, light and make sure that soil it is growing in is very well draining soil and in a container with drainage.
