This is the link for the Facebook Hypertufa Gardener Group. They are all about HYPERTUFA and not succulents but have been a wealth of information for me.
https://www.facebook.com/group...
and once you are in the group, look at these posts:
My original question on harsh outdoor climates and hypertufa:
https://www.facebook.com/group...
Several posts from people sharing their recipes for outdoor hypertufas in response:
Ontario Canada, Zone 5:
https://www.facebook.com/group...
North Carolina:
https://www.facebook.com/group...
there are multiple other posts but these are specific to OUTDOOR in nasty winters troughs.