In a real world scenario, the difference 52 & 60mpg will be negligible, as the figures are based on WLTP.
Whoever is disabled & claiming the disability benifit, should have more room however, consideration needs to be given to the driver even if not disabled so to ensure safe control of the vehicle.
Is the Nissan Qahqai E-Power with in your £ range, as that would offer a happy medium for both front and back passengers.