I have not floated the upper end of the river, only from Rush down but I loved the float we did last year. We put in at rush and got out at shipps ferry on the white. If you fish or just take a very leisurely route you can easily make it a 3 day float(we did it in two). The area is gorgeous, and the fishing is good too. For weather you just need to keep an eye on rain upstream of where you put in. the higher you are on the river the faster it will flood. For food, unless you have a good cooler I would bring things that dont require refrigeration. I would love to take a trip carrying only a water filter, some freeze dried food and a kelly kettle. That would be the ultimate in simplicity. We camped on a gravel bar and it was nice. Always remember to drag your canoe higher than you think the water can get, then drag it a little more.
Depending on the weather we may be able to make a 2 day float with you if it is on a weekend.