Try towing a van with an EV, page-20

So on your figures that's less than a 14% increase in power generation if every vehicle was an EV. Even assuming that Australia is somewhere near the very steeply increasing part of the EV adoption "S curve" we won't see 80% adoption for at least 10 years and most of those vehicles will be in the urban areas doing less km per year than the remote area owners. I would suggest that power generation would have to grow more than 14% due to population increase and extra per capita demand from our power hungry society anyway.

20 kWh/100km isn't conservative, it is quite high especially for an urban biased EV fleet. The current Wheels Car of the Year, the Kia EV6 and Australia's top selling EV, the Tesla M3 both use less than 15 kWh/100km. Now although the exterior dimensions of both those vehicles are "mid size" they have the interior room (and unfortunately weight) similar to Australia's top selling car some years ago, the Holden Commodore. I see Australia's urban car buying public moving away from the current trend of large SUVs which are ridiculous for the city commute to something a bit smaller as well.

Now towing, when our tradies, farmers and grey nomads all swap to EVs they will hopefully choose a vehicle suitable for the task, not a Skoda Enyaq as in the OP. Even the dimmest punter isn't going to try to tow anything large with a small to medium sized vehicle unless it has been designed specifically for the task. The USA has several large SUV/Pickup EVs that IMO are far to bloated for the Australian market although some will find a home here. What we need is the drivetrain from these yank tanks put into a smaller vehicle, it hasn't been done yet but IMO someone will soon. Unfortunately they will not be cheap because of the battery size and strength of the drivetrain and body but they will be able to handle any task thrown at them.