Well here we are, just had towbar and electrics fitted yesterday, and recoding done. All checked out and working. I then got message on infotainment system saying “Update needed” - that was there before, so worked my way through the menus, and managed to get that done too.
Today I popped out to shops; a few hundred yards up the road goes into limp mode, with the ESP light briefly flashing. Carried on to get to a safe place to stop, power comes back. After a couple of repeats, it eventually clears itself. Did my shopping, and got home with no trouble. Took it for a longer run later, still good.
I’m putting it down to the system not having enough data to verify itself, until I’d driven for a mile or so. But I’d welcome opinions of those who know more than me! What’s the chances of a repeat, when the mission is critical?