What major changes to the grid are required to make EVs work and why do they have to be "smart"? Electricity consumption will increase but it will be quite uniform if everyone is switching to EVs. A few upgrades for added capacity will be needed but I don't see any major issues with that. And while all new cars have to be emission-free by 2035 that does not mean all cars in use will be. It'll take probably till 2040 to 2045 for the vast majority to be EVs and that's plenty of time to do the necessary upgrades.