Followup: on our truck at least, turned out we had a bad fuse box - apparently there are relays in it that were working intermittently, so our truck was unlocking at times, not at others.

I ended up having to smash the windshield to get into the truck (it needed to be replaced anyway, but what a mess that made).

Local LR expert found the problem, replaced the fusebox, and as our 3 year old said when I showed him the doors now open, "it's magic!"

And as a friend of mine said "electrical problems with a British car? shocking!"

 

Smashed the windshield? A side window would have been easier and less messy.
But I am glad to here that you got it fixed, to bad it wasnt a simple fix.
I do wonder if the battery cable had been cut if the doors would have opened with the key becasue there would have not been any power to the system?

 

Good to hear it got fixed. I haven't seen that one yet, so I will keep this posting in mind. Thanks for posting the resolution and sorry that I wasn't able to help on this one.