If your purpose on this trip is to suffer and be uncomfortable then pay no attention to what follows, and please don't come on the trip.
Conditions for your consideration: The average highs in May in the area are in the 70s and the lows in the 40s (Farenheit). Averages being what they are, this means we could see a blizzard. Fairly strong winds can blow persistently. When paddling this means spray and drips from your paddle may soak you over time. We will be camping at places with no facilities, and so we need to be self sufficient! The river is basically flat, but inattention and/or a log just under the water can flip you when you least expect it. Try as you might, especially with a canoe, you will likely accumulate some water at the bottom as you paddle over the hours. You can plan on your storage bags getting wet, while you want the things inside to stay dry. Everything has to fit into your water craft, in a manner that is stable and provides room for you to paddle. With a bit of planning all of the above is nothing to worry about.
Necessary gear for every individual (remember - this all has to fit in the boat):
Tents: The most critical thing is that these be compact, lightweight, and able to stand up to a strong wind. You might want to also remember you are putting these up and taking them down everyday.
Other group gear: GPS units, maps, light weight tarps, group first aid kit, group radios.
Water: You need at least one gallon of potable water a day. Sad as it is, the water in the area can make you quite sick - do not drink it. Filtration systems can work, but the water in the river will likely be quite muddy at this time of year, requiring time for settling. We will look into side streams that might be clearer.
Preferred organization: Two people to a craft, and four people to a cook group. Two or four people to a tent (probably best if the same as canoe mates). Choose your canoe, tent and cook mates well. Each food group will be responsible for its own food. We must act as a group overall, so when on the water make sure that the boat that was behind you is still in view.
Food: Remember that we must pack all our garbage out! Minimize or totally avoid cans and jars that are heavy and which tend to stink after awhile. Calorie rich dry food such as nuts, spaghetti, rice, dried fruit, powdered milk, chocolate and meat jerky are probably best. Carefully plan a menu. One pot meals are the easiest. There may not be firewood where we camp, so plan accordingly.
We will do a dry run packing our crafts one Satruday morning before the trip.