[IgorPartola]

I am thinking more something that has a high spouse approval factor. 1200 sqft, 2-3 bedrooms, normal plumbing and sensible HVAC.

[bombcar]

I’m thinking something that is technically a large RV trailer “docked” into a non-house structure that provides additional space.

All major plumbing and appliances and power are in the trailer, the extra “rooms” have nothing much but lighting.

Not sure how it’d work in practice.

[thaumasiotes]

Powering your house is an advertised feature (with additional equipment) of a few electric cars.

e.g. https://electrek.co/2025/09/28/yes-an-ev-really-can-power-yo...

To go off grid, you'd need a source of power to the car that wasn't your house.