After the pain of public charging on our way to Stoke the rest of the trip went very well. We found the public charge points in the John Street car park easily (though only one had its light on).
Unfortunately they didn’t have any signage indicating what network they belonged to. On a whim I waved an old Plugged-in Midlands card at the charger and it started to work.
We left the car on charge for the rest of the day while we had lunch and then watched the gym displays. I was able to monitor the charging on my phone like last time, but this time it completed without a hitch.
At the end of the day we got back to a fully charged i3. With its long range we were able to get home, some 100+ miles south, without a single stop.