Having a quick scout I think Octopus rates for Elec in East should be :-
Unit rate (Peak): 15.96p/ kWh
Unit rate (Off): 5.00p/ kWh
Standing Charge: 25.00p/ day
That's precisely what we're paying, off-peak being 00:30 - 04:30. That's perfect for our little EV, and this time of year at around 4 miles/kWh means ~1.25p/mile. I'll take that!