It's Adromischus umbraticola. There are 2 subspecies, Adromischus umbraticola subsp. umbraticola and Adromischus umbraticola subsp ramosa. I'm not sure which subspecies you have. They are hardy to 20 degrees Farenheit. They need some shade, and they shouldn't be watered at all during winter, so they would do better indoors by a sunny window, (keeping in mind they also need some shade). Keeping it indoors will allow it to remain dry during winter. They are endemic to South Africa and Namibia.

Wow Jay- you're the best! Thanks for exactly the info I was looking for! Perfect!