I haven't seen anything in the media about the nuts and bolts figures as opposed to blue sky aspirations.
It has been looked at seriously in Tasmania quite some time ago by the Hydro and more recently by AEMO at a national level.
Both reached much the same conclusion - from an energy perspective, that is total electricity consumed, it's no big deal but there's the potential for problems if consumers try to charge them at the wrong time which plausibly they will in the absence of action to make sure they don't.
Where that charging concern arises is that most homes are currently on flat rate tariffs and a substantial portion of vehicles are parked at home sometime around 6pm and left there until the following morning. That being so, it seems logical to assume that most will plug the vehicle in to charge at about 6pm - and that's the very time when electricity demand peaks even without EV's.
It then splits into an issue of engineering versus reality in the real world.
From an engineering perspective well a $20 timer from Bunnings will fix it no worries. Just like using the delay start on your dishwasher or clothes dryer fixes the same problem.
Trouble is - about delay start on the dishwasher. How many here really load it up at 7pm and set the timer to run it at 2 in the morning? The odd energy fanatic might be doing it but in the grand scheme of things no, consumers don't do that they tend to run it straight away. Same with anything else where there's no real reason to run it at a particular time - very, very few will consciously shift that load unless there's a financial incentive and even then a lot won't do it optimally.
What's needed there amounts to engineering + marketing but no politics. We need systems that are dead easy for consumers to use (marketing), which charge the car by the morning (both) but which don't lead to a huge spike in demand whilst doing nothing to lift minimum load at 3am (engineering). It could be done with some smarts but by default it won't simply happen - currently for sale EV's don't do that for example.
So it's all in the implementation. Do it right and EV's can bring a lot of benefits to the grid, increasing minimum load more than they increase peak load is about as a good a concept as it gets when it comes to electricity supply. Done wrong however, and that's the likely default, it'll be the exact opposite - increasing peak load whilst adding little if anything to minimum load isn't at all nice.
My view is firmly that the time to get it right is now not once there's been a few blackouts and $ billions wasted by ignoring it. And please, please, please keep politicians as far away from it all as possible - there's a role for engineering and since it's a consumer device also marketing in the approach to how it's done but there's no need for clowns.
FWIW - I don't own an EV but some recent electrical works have made provision for it most certainly. That's for controlled load (off-peak) charging of course not peak
.