As this is in the context of Montana,

1. not every part of the U.S. grid is in dire need of improvement, most homes have access to 240v most of the time. (with the exception of the 1 state that has assigned fire damages to their utility. And, most vehicles are charged at night, outside of peak demand. (also, the Tesla wall was a technology that further decreased demand on the grid)

2. Most of Montana is going to have off street parking, be it a barn or garage (and with at least 120v) mostly by the necessity that sub zero temperatures ~2 months of the year freezing anti-freeze, batteries -- and that you can't use an ice scraper to scrape off feet of snow.

"most" of the time - I think you don't realise how bad this is compared to say the UK or France or Germany

Sorry, for states other than California, this year, that should say all of the the time; And part of why every house is wired for 240 is because our dryers and hvacs all use 240.

True but the equivalent of that else where is the 415 V cooker circuit.

All the mains sockets in uk houses are 240v - this is whey you never see an electric kettle in US homes

We're really conflating apples and oranges here as the voltage is only half the equation;

By code, US 2 phase (120x2 == 240) is going to be wired with lower gauge wire to provide more overall electricity. Typically, the 240v is going to be capable of providing 600 total amps (though there are cases where 400amp is served); with a typical breaker at 30 or 40 amps. compared to a triple 415 providing 8 or 15amps.