How Much Fuel?

Ok, so I need you guys to check my math. I have been having a hard time finding information on how much fuel we need to bring. I have to buy the fuel and bottles in Victoria the morning I get there. I found a couple vendors that carry the products, but then realized today that Mountain Equipment Coop (the mecca of outdoor gear in Canada) has a location 1 km away from the harbour area where we are trying to get a hotel. They have absolutely everything you could possible need on this trip. I will likely buy from them. I then found on Mountain Equipment Coop's website a helpful hint/tip that has brought me to a conclusion of how much gas to bring. However, I need you guys to do the math with me so that I am not the one held responsible when we have no fuel left and we are only 6 days on the trail.

They say the general rule of thumb is that in normal summer like conditions a single person will use 4oz of fuel per day for quick cooking meals and hot drinks. That means we will need approximately 12oz per day for the group. The MSR fuel bottles come in 3 different sizes, 11oz, 22oz, and 33oz. So I figure that if we buy 3, 33oz bottles and 1, 22oz bottle we will be ok. That gives us a total of 121oz...if the assumption of 4oz per person are accurate we only need 96oz for the trip. We will have a surplus of 25oz which will last us another 2 days if necessary. Or provide us with longer burn times for bigger meals. We can help share the load in our packs.

Let me know what your thoughts are. We could cut it closer and do 3, 33oz, and 1, 11oz bottle, but that only gives us a reserve of 14oz (or 1 day of cooking for all of us). The load difference in our packs is only 11oz, so I am not sure if I would risk the weight over comfort.