I must add that I purchased two at once, and the other cactus was left in a cold basement window. It did not wilt.

I can't say, only because they are in a pot and not in ground. When in the ground, they will indeed shrivel and almost "melt", but they will pop back once warmer temps hit.
I am in Wisconsin and have mine in a pot in my basement. It has just started to shrivel up. I stopped watering it in November and won't start again until March.

Hope this helps a little.

Nancy

Thanks for that, hopefully it springs to life when weather warms. For now it's in the gh kept just above freezing.