Just inside the outer bronze frame, through the wood. The rudder is not likely to fall off, but wheel steering will fail eventually and the stock could break or the drifts and bolts could fail(I've replaced them, but...).

I can't think of a retrofit to my emergency tiller(because of the binnacle and that the rudder post comes through the cockpit sole) that would make it feasible to use for a longish duration, say overnight. A hole through the wood just inside the bronze frame would allow a line with a knot on each side, lead to spinnaker winches. It would be easy enough to rig in calm seas treading water, a bit of a problem in a seaway(emergency tiller for that). Holes are cheap.