my group has taken 14 foot keelless river canoes through nym and batch in some pretty terrible storm conditions and havent had an issue with the size. if the paddlers are competent that shouldnt be an issue.

id worry more about the structural integrity of that canoe. i dont like the looks of that big dent right in the middle. chances are if you were careful you could manage a full trip if you brought a role of duct tape as insurance. the worry-some issues id have would be tripping on a portage and how that dent/crack would hold up from the shock of an accidental drop and the inevitable big wave that drops you down on a big rock.

we are always quite careful with the getting in/out part and try not to run up on shore if we dont have to. its always worth getting your shoes wet.

to sum it up, theres plenty of things to worry about up there, and since you even mentioned the canoe, it shows you are worried. id say leave that one behind for this trip and see how it performs around your house.