Electricity needs when the grids down.

[Joe]

For serious long term outages power usage can be split into two halves, one is heating/ hot water etc, the other is powering lighting and electronic appliances. I would give up trying to heat a house on solar or wind, it’s just not viable and it’s easier with gas/ wood/coal etc.
For number two you can easily get by with solar/ wind etc. Led lighting is cheap and advanced so there’s no need to be in the dark. For tv and computer use you can purchase a basic inverter and run it from a 12v/24v system.
The tricky one tends to be freezers, if you have plenty of solar/wind available you can just about run it from an inverter but ideally this might be better on a generator.

Some interesting comments regarding smart meters, I have avoided these because of two issues.
1. Privacy ( someone can tell a lot about you from your power usage)
2. Incoming mains contactor ( you can be disconnected in seconds while others take priority)