Sorry Ian, I was assuming you were replying to Wonky’s message, I do apologise. ?
Wonky, there is one car that would fit the bill but most dismiss it, Peugeot Rifter/Citroen Berlingo.
Either will get you into the 50’s with the mpg and they have even more space than the Alhambra(provided you go for the long version).
I ordered one of the Peugeot’s in Nov and it’s arriving in 2-3 weeks, can’t wait to get rid of my Alhambra and start to enjoy driving again without thinking about the cost of fuel.