Not quite.
You looked at the UK production and stated we needed an additional 8 plants to make up the production kWh across a year. However, that's assuming that the UK runs all energy production flat out.
It doesn't, our gas electricity production for example largely follows demand, whilst others like Nuclear provide constant baseline. Coal for example is brought online during winter when electricity prices are high enough to make coal economic.
What does that all mean? In simple terms that don't address open/closure of plants, we can meet EV demand by running more of our energy production more of the time with reduced variability in production throughout the day.
See
www.gridwatch.templar.co.uk to understand to rise and fall in UK (and French) production.