Thanks for the comments Mr. Swayback...
After reading this thread, I'm inspired to add a sampling of excess Haworthias to my dry succulent bed and overwinter them outdoors to see just how hardy they will be. I shall have to do so early in summer so the roots will be established before the first freeze. I will bet they will be far hardier as I'm finding the same with other succulents in that bed. I would suspect the windowpanes will be less cold hardy.
I have enough excess Haworthias that I will also consider sharing but it will have to be later in the spring as things are hectic for a few months. I will ask that if anyone is interested, please bump me later in the new year...
