Excellent write up!
I can relate with you riding on snow and ice and I felt the tension that you must have felt while reading your report.
My wife and I went down on a snow/ice covered country road a couple years ago. Full ATGATT so no injuries. The bike was brand new and I remember seeing it spin a couple of 360's on the head thinking it was going to be toast, but the head guard did it's job (as well as the OEM Panniers.) The bike was still running on its side and after quickly checking with my wife, I ran over and hit the kill switch.
Glad you made it home safely!