Someone has to build quite a few more power stations though.
Assuming you're talking about swapping a large fraction of the car fleet to EV, not just a few here and there.
That's a substantial increase in total electricity demand. Enough to radically impact the load on the grid.
And if you end up burning natual gas / coal to meet the marginal increase in demand - as would seem fairly likely - then much of the thermal conversion losses you're saving in the higehr efficieny motor just get shifted to the furnace in the power station and transmission/distribution system; so that can erode some of the efficiency benefits.
I guess you could require for every new EV that they also install roftop solar PV and basically buy a spare battery of near same capacity as the car. that might push the up front and periodic replacement cost a bit though - quite nice for the running costs i guess.
Another good alternative is to try to convince people to get together and share their electric motors in things callled trains and do as many trips in those as possible - that's not too popular with most people unless the road congestion is really bad. Something to do with sharing being communism i think,
And flood loads of valleys to create massive hydro power stations?
Norway's low density gives it plentry of cheap renewable electricity (per person).
In my country we have loads of people living in valleys, so we'd probably not get away with building that much hydro generation capacity.
Although there's a whole area called the "lake district" that is literally asking for it.
xkcd #2948: Electric vs Gas ( xkcd.com )
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