So, it turns out that the GoPro adhesive mounts don't work too well when it gets cold. Despite the fact that it was a brand new mount, it still failed.
yeah no kidding. those plastic mounts seem to have a finite lifetime, it's just a question of whether the lifetime gets lessened by something like weather..
It kinda sucks if I'm honest. If there were metal mounts available for a reasonable cost then I'd use those, but the entire GoPro mounting system is a bit... meh. Call me old fashioned, but I like a good tripod screw.