Power grids are quite large, so any fluctuations across the grid is going to be minimal. They are quite good at modeling these things, otherwise we'd have rolling blackouts quite often. For homes it's the last mile that's usually the biggest limiting factor.
But I agree with what you said, for /most/ people anything more than 2kW (so 240V/10A) is more than enough to charge up overnight. A perk with CCS2 is the support for 3-phase power delivery. With very simple wiring and some smart(-ish) electronics you can opportunistically deliver around 11kW to a single car, or divide it with other house appliances or other cars. It's fairly common with 400V TN-system in some parts of Europe, which makes the support of 3-phase in CCS2 very handy.