Probane, isotubane… etc fuel canister.

My 220 g canisters boil 16 ounces of water in 3 minutes, 4 per day, 8 days per canister, so that would be 96 minutes. But time isn't so good an indicator, because some stoves are hotter, some colder, amount of water boiled is better.

But, I think you will have plenty of fuel.

Yes, 220 grams is plenty.

For two people, 3 days x (breakfast + dinner each day), I could easily do it with a 100 gram canister.

Trick #1: Most stove/pot combinations are more fuel efficient with a moderate flame. Not full throttle.

Trick # 2 Watch your pot closely while it comes to a boil. More heat once you are at boiling does no good and wastes fuel. Aim to stop it just before it boils. Look for a tiny bit of steam coming off. Don't wait for a lot of steam from a rolling boil.

Trick #3: Then let the noodles / rice / F-D food seep in that hot water, DON'T simmer. Throw a towel or cotton t-shirt or hat over the pot to retain the heat. This has numerous benefits. You burn less fuel – duh. And you burn less food! – a viscous mix of food and water often doesn't convect enough heat away from the pot bottom. By seeping instead of simmering, you eliminate that risk. And, while seeping, you needn't stay near the stove. Set up your tent. Prep some other food. Look for shapes in the clouds. Then, instead of 5 minutes of simmering, you give it 6-7 minutes of seeping, check the temperature and the "doneness" (really, how much it has rehydrated). It may well be an ideal temperature to eat. If not, give it a low flame for a short time while stirring constantly.

Back when I simmered food, I had to be attentive all the time – looking for boiling over and stirring the food. Now, with seeping the food in a hot pot under a cozy, cooking takes much less attention and less fuel.

Just to clarify, you mean 8 meals total? Unless you plan to camp at the trail head before/after your hike, 4 days/3 nights usually means dinner the first, second, and third nights and breakfast the second, third and fourth mornings, so that's only 6 meals. Even allocating 16g of fuel per meal (which is a LOT of isobutane!) you should be able to do it easily with a 100g canister.

If in doubt, get a good scale (accurate to 0.1g), cook a test meal and check the weight difference of the canister to see how much fuel you're actually using.

Take the 220g canister. Always better to have fuel left over than run out before your last dinner. Weigh the canister before you start and at the end, then you will know how much you actually used for next time.

Trick #0: Use a windscreen around your stove. In a light breeze your fuel consumption will double without one.

Trick #3: "a viscous mix of food and water often doesn't convect enough heat away from the pot bottom."
Too true! Add plenty of water to make a soupy stew, or just turn the stove off and cover the pot as David suggested.

That's what we in the lower 48 call it, David.
;-)

Full disclosure:
I don't speak any Alaskan dialects….

Agreed. My bad. Steeping. Like tea leaves. Not seeping like a leak.

"Trick #1: Most stove/pot combinations are more fuel efficient with a moderate flame. Not full throttle.

Trick # 2 Watch your pot closely while it comes to a boil. More heat once you are at boiling does no good and wastes fuel. Aim to stop it just before it boils. Look for a tiny bit of steam coming off. Don't wait for a lot of steam from a rolling boil.

Trick #3: Then let the noodles / rice / F-D food seep in that hot water, DON'T simmer. Throw a towel or cotton t-shirt or hat over the pot to retain the heat. This has numerous benefits. You burn less fuel – duh. And you burn less food! – a viscous mix of food and water often doesn't convect enough heat away from the pot bottom. By seeping instead of simmering, you eliminate that risk."

+ 1

To which I might add: Select foods that absorb sub 212 degree water readily. Cous cous is excellent, as is dehydrated mashed potatoes. Dehydrated split pea soup, black bean/pinto bean/corn chowder soup also work very well. You can add olive oil or cheese to all of these to increase the calorie content and flavor, as also dehydrated veggies and spices for flavor.

Well, if you turn down the burner once you get to a boil on each meal, you will most likely use no more than 10g of fuel per meal..8 x 10 is 80…

I dont see a problem with a full 100g cartrige on that trip. I would use a 110g MSR Isopro just for a little added insurance.:)

One smart thing to do would be to take a used canister and using an accurate scale ,check how much fuel you use on a practice run making a typical meal.If fuel consumption is an issue its,best to have some sort of a baseline to calculate fuel consumption..