We have a single phase 80A supply
I can't see the problem, a single phase 80A supply is entirely enough to keep a couple of EVs charged in normal usage. I live out in the country, even when I was working I didn't need to do more than 30 miles in a normal day, now I'm retired I doubt I do 60 miles in a week in a car, all sub 10-mile short trips are Pedelec and the occasional non-Morgan long journey would be easily planned around if we had an EV.
As it is, our Fiat 500 is only 5 years old and there's no sensible sustainability argument to change it for at good 5 years or so, but when the time does come I'll have no qualms whatsoever about switching to an EV.
That's just you though Tim and the numbers may appear to stack up, although you haven't mentioned or drawn attention to the power of the charger you would use. Let's say you have a 100 amp trip on your home supply and 80 amp rated RCD (safety leakage trip) as we have on our recent consumer unit installation. That's 19kW total, but If you have a power shower that would probably take 10kW, add in electric cooker, kettle, microwave, toaster, vacuum cleaner, heating pump, lighting, TV etc and you would already be close to that 19kW. Ok it's very unlikely to have that combined power draw but mentioned by way of illustration, although it assumes no direct electric heating.
Now consider your home EV charger, taking a Nissan Leaf as an example. They offer/suggest 3 or 7kW home chargers. You will get away with a 3kW charger providing a full charge in 14 hours, but the 7kW one will likely cause issues at some point or other during the up to 6 hours its on. Lets be super fair and suggest the battery is usually only one third depleted when its put on charge. Sadly this will make no difference to the power draw from charger. It will draw power at its max limit for most of the time its on due to the efficiency of the batteries. Some sort of off peak circuitry may help but would require substantial changes to consumer unit and wiring. Oh and this is just considering one small EV BTW.
Early adopters of EV's have gone into this with their eyes open, aware of re-charge points, usage limitations etc. and seem to have developed disciplines to cope comfortably, mainly adopting remote charging points I would suspect though. But what of Joe public when he/she is forced to adopt an EV and has a typical 8-10,000 miles travelling per year possibly on each of two vehicles. Never mind my average mileage as a retiree which has recently been in the order of 16,000 miles/year spread over three vehicles.
Improvements in EV's themselves with regard to battery performance and range over the next decade or two can only worsen the home charging scenario and as suggested there are no plans for homes to receive industrial three phase supplies.
