So much depends on what you are cooking: boiling water only for freeze dried meals and instant cereal/beverages versus frying fish and simmering pasta and making pancakes or french toast, for extremes. And, cool weather increases fuel usage both because of the increased heat loss during cooking and for the increased hot water for beverages.
These use figures may give you a start, however: two of us, for a week, typically pack two liters of white gas, using a Coleman single burner dual fuel stove (model 442). No freeze dried meals.
Bkfst is a liter of coffee or hot chocolate, hot oatmeal, dried fruit, with one or two luxury breakfasts packed consisting of pancakes or muffins or stir fried spuds.
Lunch, no fuel used.
Dinners we splurge on fuel, with stir fried vegetables most nights, enhanced with canned meats or fresh caught fish, cous cous or rice for carbohydrate, with instant potatoes one or two nights. Warm cooked pudding and a hot beverage add to the fuel toll, as do raw potatoes, boiled fully for dinner, or partially for use at breakfast stir fried.
This works out to about 0.3 L per night, and we have never run out, typically returning with 0.5 L or more, depending on whether we catch and fry fish. Our 442 is better at simmering than your stoves, and has less heat output on high, so your stoves may consume more fuel. Avoid maximum heat output, using a flame which puts most of the heat on the pan or pot. Full output throws a lot of heat outside the cooking vessel.
Edit: another fuel waster is pasta which is boiled in water not incorporated into the meal, hence our use of rice, cous cous, and instant potatoes. Raw spuds, yup, the boiled water is tossed, a concession to the taste of fresh potatoes, so we might have just two meals employing boiled potatoes.