I grew up in deep river and used to fish in rolphton, deux rivere section.
Its all flat water next too zero current until petawawa. The only portage is a dam in swisha. Its pretty easy and boring just paddling straight all day. Just measure it on a map and 3-4 km’s per hour paddling. There are way better and more scenic (less developed rivers no cottages and towns) to do. Demoine, callounge?? that u could take them down if you don’t mind white water. Those are some rivers I used to due at the end of year with my school. The mattawa is an easy 2-3 day trip with some easy II.
E-mail me back if you have any questions. I can try to get in touch with my old teachers if you have any questions about trips