Many succulents are opportunistic (meaning they grow whenever conditions are good) or summer dormant (meaning they grow in cooler weather), so it's not a given that they go dormant in winter, though some do. From the pictures it looks like you have opportunistic growers that need some water all year.

That being said, if you can't provide the same light and warmth they were getting in the summer, it's probably best to ease up on the watering during the winter to avoid etiolated (stretched/weak) growth.

There are a few interesting current discussions about winter care here and here.

Succulents will overwinter well in cooler temps, with reduced watering, but should still have good light. I can see quite a few plants in your windows - but many seem to be etiolated. That means they are not getting enough light.

How warm/cold is it where they are kept?