Where are these places that give you massively discounted electricity at night?! Done away with around here many years ago… I wouldn’t rely on them always being there - obviously especially if everyone starts charging cars at night as it will cease being off peak and the reason for the lower price will be eroded.
There are multiple electricity providers in the UK currently that have "EV tariffs" where they give you substantially discounted overnight/off-peak rates in exchange for a slightly higher daytime rate in order to encourage overnight charging. Often up to a maximum specified number of KWh per cycle.
In previous times they used to offer a tariff called economy 7 which worked in conjunction with so-called storage heaters. They would charge during off-peak times and provide heat during more active hours. (disclaimer, I've never lived in a property on such a scheme but definitely saw a few in my student days)
Octopus (https://octopus.energy/) do 7.5p/kwh 00:30-04:30. I haven't used it, though, no idea if there are catches.
They are becoming more common here in the US. Although the one that I see most is more like a 3-4 hour peak period with very high rates and lower rates the rest of the day.
Very roughly, UK prices are ~£0.2/kwh electrity and ~£2/litre of petrol. Per mile I make that £0.2 for petrol vs £0.045 for electric. Although you could probably get to the 1/10th figure if you always charged on the super-off-peak EV tarrifs.