Hi Bill, got your PM and thought I'd reply here. I'm not sure exactly what has changed since I worked there (last in 2009).
As stated above, getting your crew on board with lightweight approach makes a big difference in lowering the weight of your personal gear. Yes, the three people in each canoe will pack their personal gear and a tent into one plastic bag-lined"gray whale" portage pack, which is a large Granite Gear. An adult can fit completely inside one, yet many crews barely fit everything in there. Making sure you share gear like toothpaste, sunscreen, fishing tackle, etc. goes a long way here. Also having compact sleeping bags (I haven't seen it lower than 35 degrees at night, more commonly in the 50s) and minimal "extra" clothes helps. Don't skip the sacred dry socks and dry camp shoes...most scouts depend on these to prevent painful fungus.
Clothing I wore/carried:
Long underwear top
Running/hiking/thrift store dress socks (wet)
Thick warm socks (sacred/dry)
Moccasins or old sneakers (dry)
If projected lows below 50 or lots of rain, may add thermal bottoms
If projected lows below 40, add light fleece or thermal jacket
*I usually didn't pack a sleeping bag. I slept in a silk liner bag 90% of the time--which I don't recommend for clients--so that may tell you that I'm a bit of a warmer person. I was never cold with the above, but keep in mind that scouts are tired and wet at least on their lower body much of the time from portaging. Doing it again I would probably wear a button-down sun shirt instead of t-shirt.
Finally, don't allow every person to bring "extra" hydration packs, daypacks, fishing kits clipped to their Nalgenes, etc. You will have to hand-carry paddles and bottles anyway, so at most have one tiny daypack pack per boat for sunscreen, camera, rain gear, etc. (but this can easily be nixed). Whoever carries this will ALSO have to carry one of the other two packs or a canoe.
For group gear, it's up to you what you want to bring your own or use from the base. Figure out what tent configuration works for your crew: I have seen crews carry their own tents but if each adult brings his own two-person mass-market tent, it won't save much. Northern Tier will provide two-person and four-person tents, so in a crew of two advisors and six youth it usually works best (within the regulations on youth/adult cohabitation) to get two 2-person tents and one 4-person model.
One could bring group pots, stoves, etc...but I have very rarely seen this done. This is because the style of food and cooking is fuel-intensive and heavy by nature. I simply recommend asking your interpreter if there are any pots or pieces of group gear that you could get away without, and then thanking him or her for removing one cursory pot out of the 4-6 you carry. If you get a talented dessert gourmand or fish-fryer for an interpreter, you may not mind.
I'll try to keep an eye on the thread; let me know if you have any further questions.