The difficult task was trying to determine what the loose wire was dangling from underneath the dash in the drivers side footwell. One needed to be a midget or contortionist to see up in there. Nonetheless, I jiggled the connectors in the left hand footrest under the carpet and reconnected the battery (having now been left overnight) and it started.
I'm still not sure what exactly resolved the problem, but I'm seriously thinking of getting rid of the SD4 after such a frightenening episode. Stranded in a remote, freezing location for no apparent reason in a vehicle designed to go offroad. Not a pleasant feeling.
Offroad Vehicle manufacturers, including Land Rover, need to have a failsafe mode of basic vehicle operation that can overcome the rediculous number of sensors that can contribute to the immobilisation of a vehicle. Surely, many faults could be addressed by warning lights instead?