I thought the entire USA was on 110v? Obviously not.
NZ is all 240v, although at peak times the voltage drops and the microwave won't start.

TonyP, most homes built since about 1960, in the US, maybe just in some states, have 220/240 at their electrical service. Not all houses will then have the 220/240 routed into the house, it is just available. Other houses that have electric stoves and/or A/C will have the 220/240 wired to those units. Most other than those use 110/120.

We don't need to add in EV's,we have enough brownouts and blackouts without them.

I bought a gasoline powered 10kw generator about 11years ago, because at the time we were renting a house that didn't have 220/240 and I needed 220/240 to run some welding machines. (I welded outside, never inside, with at least 2 fire extinguishers one by my feet and the other about 10 feet from where I was welding). It was single fuel, but I got an adapter to be able to run it on 3 fuels. Gasoline, propane and natural gas. It is 10 kw on gasoline, about 8 kw on propane and somewhere around 7 to 7 1/2 kw on natural gas. Never the less I run it occasionally and while I have never had to use it for a power outage, I would run an outdoor extension cord into the house to power the freezer, refrigerator and other things as we need, for a few hours every day.

When I had my Generic sales person come out I asked him what size Generic I needed.
When he told me, I told him that I wanted the next size up.
He also installed a whole house surge protector.
When ever we have a power failure I tell my neighbor next door to throw a extension cord across the fence and plug it in. He runs his TV and Refrigerator. have never had a problem.
We paid $8,697 for the unit and Instl. We have had it for 11 years now and with proper maintenance have never had a problem.