Remotest villages in India were doing gobar gas plants in 80s/90s. What you are saying is possible.

If you have enough cows/biomass, perhaps you can have a home biomass to methane converter. Then you can use it for cooking, heating, etc.

You can convert a petrol car to a CNG car.

You could also have a coal to liquid plant in the backyard and generate diesel or petrol.

You have to do without any cooling though, fridge, AC, etc. Cold can't be created. Without electricity, just with chemicals fuels, it is unlikely.

I don't think they have to worry about lack of access to cold for the next few months. I believe you're accurate re: India and sources of biomass in that context and the possibility of some processing/conversion, but how representative is that of the resources at disposal of the typical person in Ukraine? I imagine more urban residences with electricity and not a lot of cows.