HI Memmil, I typically do not use any fibrous or wood chips on my succulent media,. Got to keep it much more well draining. I would either add more perlite or pumice. I also agree with Will, you may have to move it closer to the window or maybe supplement with grow lights.
17C temps is okay with it. I have mine staying outdoors even at 0C overnight, as long as you keep it dry, but our temps do rise during daytime between 10C to 12C during winter. But if you get snow, then definitely bring it in, and augment with grow lights if your sunlight is too short as well.
