Erm... shit springs to mind...
If the door wont unlock from the sill lock button, then it sounds like it's superlocked - and then you are in for a world of fun, because the feed to the door latch to control all that is in the passenger door... between that and the outstation
If everything is dead, then it does point towards the connectors in the door jamb that OB has linked to, as everything stopping in the passenger door will most likely be either the power/ground or serial link to the outstation that has gone down.
I'm just trying to think if it is possible to reach in from the front if the glove box is removed, to get to the connectors from the inside... I have a bad feeling that those wires run up in between 2 parts of the bodyshell.
I would keep trying it and hope it's an intermittent problem, that has it come back to life for long enough to unlock the door, so you can get into it! but if not, then it is going to need some surgery to get the door open if you can't get to the connectors from the inside (even if it's to wiggle them and temporarily get communication back to get the door open)
'06 4.2 Supercharged Black/Cream "Jess" -- Bought April 2021 (NZ)
'01 4.6 Vogue Black/Lightstone "Snog" -- Bought Jan 2012
'99 4.6 HSE Cobar Blue/Lightstone -- Sold March 2009
'95 4.6 HSE Epsom Green/Tan -- Traded June 2008