"I've noticed that I use something on the order of 1.5 fl oz (44ml) of white gas on a solo trip per day. For two people, I find my usage is something on the order of 2.25 fl oz (67ml) per day."

I have limited experience with Coleman fuel stoves. But on one summer 2-week trip with 12 people in our group, we used 3 Whisperlite stoves at meal times (breakfast and supper, dinner was a simple snack). We packed roughly 2 oz per person per day but since the bottles need airspace it worked out to about 1.2x that amount. Each of us was assigned a 33oz bottle. (Some of the gals "lost" their fuel bottles in the guys packs with our consent.) I fugured we carried about 330 oz for the group or roughly $40-45 of fuel. We ended up with 3.5 bottles of fuel at the end. So we probably only used about 1.4 oz/day/person including stove priming. And with so many rookies with white gas stoves, I figure that usage is on the high side as we probably wasted fuel in the priming stage.

That's quite a bit more efficient than if we had packed alcohol stoves but less efficient & less expensive than if we had used canister stoves.

Presumably, we gained efficiency with such a large group vs. your average with 2 people.