I'm not proud to admit (but I was interested to read that I'm not the only one) that I've gotten into the habit of making a tarball of my working directory and

I'm not proud to admit (but I was interested to read that I'm not the only one) that I've gotten into the habit of making a tarball of my working directory and .git directory before large rebase operations between multiple feature branches, because like you I've lost work because git got into awkward states I couldn't get it out of without losing work. A full system backup of my laptops is taken roughly every three hours so it's quite hard for me to lose more work than that. However recovering from a failed rebase without losing changes can also consume a sizable amount of time, which explains why I'm still careful and take precautions anyway.