I have no idea what my lowest cadence is, because if I'm working that hard, I'm not looking at the Wahoo in that detail. And it has gone into auto-pause when I've been at the slowest anyhow. It will probably be somweher between 20 and 40 RPM,
[EDIT] Just looked up one of my rides up Witches Hill, and the loest cadence was recorded as 47, so maybe not quite as low as I suggested there.
I wonder over what period a Garmin (or whatever) averages cadence. The display flashes to zero within a couple of seconds after ceasing pedalling and comes back up to a believable number very quickly when ceasing freewheeling.
Clearly at the crux of a climb a rider's balance will determine how close to a track stand they can cope with.
I feel some experimentation coming on, but the jeopardy is as
@IanH describes, going to the top-of-dead-centre brink, clipped in.
Climbing Wrynose (below) going west was interesting: I was getting chain suck and when that happens on a steep climb , you're down, albeit at 0kph. Had to manage Hardknott immediately after in the middle ring (42t) so 37" gear.