SOP =
Standard Operating Procedure.
Pilot Incapacitation is a
non-standard event.
At this point, you are fast approaching the point of having to think "outside the box", if not from a procedural point of view, a decision making one.
DODAR is uniquely down to you now.
Batty,
You can surely see the merits of a continuation of the approach under the circumstances?
If you are worried about you personal ability to assess the continued ability of the aircraft to land in CAT 3 conditions, and subsequently execute/manage the landing/roll-out, a few approaches in the sim should address that concern...
What in JARs wisdom do you do if you then get a system unservisablity in flight that makes you Cat I and you are down to fuel for only a Cat III alternate, since you left base as Cat III?
I'm curious... The answer to your own scenario, namely, an incapacitation and all out CAT 3 weather, is?