My youngest SiL, a real petrolhead, was given a 7kW generator by a client, as he'd mistakenly bought two! I allow SiL to keep his Caterham car-trailer in the garden and we often get power cuts so he gave it to me, after trying it but finding it difficult to keep going for some unknown reason.
It transpired that there was no oil in the generator and the bearings had seized! So much for him being good with motors.
Fortunately we were able to resurrect it and it now sits ready for use, having already powered my electric chainsaw at the bottom of the garden (because the bearing in the petrol one had seized).
However, it is bl**dy heavy so I don't know quite where to site it nor how to run a power supply from outside to inside in a sensible manner. A switch to disconnect from the grid might be a good idea, as 7kW should supply all of our needs. I don't know how long the petrol tank would remain full.
Last year my son and his family were living in a touring caravan in the garden. A large awning gave them extra space but it was cold, so he bought a
diesel heater (and used my oil). He now has a house and I have his heater but finding a way of getting rid of the exhaust fumes is another problem which needs to be solved before winter. We used scaffold pipe to get it out of the awning.
As for wood, I used to buy 2.25T of firewood for £125 approx 5y ago. This year it is £285 AND it isn't kiln dried (but don't tell anyone).
Gordon