Paul, you are gobbling up the anti EV propaganda as fact. So much BS out there.
My 5Kw PV array provides enough power for my house , plus all the power my Electric Car needs, plus around $250 in FIT credit.
I have a DIY LandRover conversion and it has a "J1772 Nozzle" Teslas do not. I did 5500km last year @ 28kwh per 100km = yearly consumption of 1540kwh . From Jan '18 to Jan '19 (FYI 28kwh /100km for a 1500kg vehicle is not very efficient , A 2500kg Tesla uses about 22kwh per 100km.) My E-Landy has a 3.3kw charger & plugs into a 15A point, draws 13.5 Amps .
5kw PV array produced 6387kw for the last 4 quarters .
After EV charging left 4947kw. 4560kwh household use & $0.71 FIT = $274 credit .
So I put more back into the network than what I used.
You talk about those 300 people you referred to in a hypothetical housing block, I don't believe that is a typical Australian situation, is more like China and they have no problems dealing with such demand. Typically accomodation like that is not for commuters more like public transport to work. Cruise around China in Google Earth and you will easily find solar farms like this
Google Maps
Anyway bottom line its about choices, your choice is to continue buy petrol , I'm fine with that . I also have a petrol car and a Diesel 4x4 , but they only get used when I have to drive a round trip more than 80km. neither of them have been driven more that 350km on any single day , and then only 3 occasions in the last 12 months. ( Any modern EV can cope with that )
Typically I do about 25km a day in my E-Landy and charge once every 2 or 3 days . 10 million people doing the same as me are not going to put a burden on the Electrical Grid , How many people will be doing an Interstate run every day , 1000 ?? 5000 ?? who knows but I'm pretty sure the grid can cope with them . Moreso , especially now that theres no Automotive Industry and bugger all Manufacturing of any type in Australia , the grid used to cope with that load.