But hey you could save on heating?
A single circuit using 10mm TPS would technically be enough to run what you’re describing. Might be pricey though, I’d probably take the excuse to get 3 phase installed so I could get access to the stock of used 3 phase machinery.
In the US it's common to get 200A 120/240V split-phase service. We're talking about the wiring inside the house, though.
How do you think everyone here is charging their electric cars at home and running our AC and electric cooktops at the same time if we didn't also have that? :)
You need to derate for constant loads here, and I assume you have to do that in NZ as well.
So, no, not a "uniquely US issue".