The goverment comisioned studies several years ago and concluded that EVs will result in an additional 10% increase impact in Britain, and they considered the grid capable to sustain that without any problem, not only that, the grid is ongoing sustaining development as we speak and money being invested on it because renewables or not smart grids are beneficial for a number of reasons

and if britain grid can sustain it, I bet my arse that Germany and France aren't any far behind