Remember you are home, no wind and likely have a insulated stove base etc.
Do not forget to take a decent wind screen, Alu. roof flashing works well.
What will really kill your fuel use figures will be simmering times. Boiling is easy if that is all you do, do not use your stove to keep food warm.
For a warmer I use a home made candle lantern with a sm. tub candle. I cut a window out of a short 6oz. soda can, used a
piece of clear plastic from a soda bottle to cover the window,
punched a air vent, I hang the lantern by the pull tab if needed. To use it as a warmer I just set my pot on top of the can, the window cutout does not affect the strength of the can if you do not cut out more than 20% of the total dia,
Total weight 1oz. tops, burn time 2-3 hours.