Two summers with a canister stove
A 230 g canister lasts me about four days of breakfasts and dinners for one, a little less above the tree line. Most of the difference comes from wind, not altitude.
A pot lid and a small foil windscreen cut boil time almost in half on exposed ridges. Keep the screen loose around a canister stove so the canister does not overheat.
In cold weather the canister goes into the sleeping bag overnight and into a jacket pocket before cooking.