I only take one thing: a partial roll of duct tape, (Actually I think it is gorilla tape).  Now, obviously anything can happen on a trip, but I'm not shooting rapids, so that reduces my damage possibilities to primarily: I didn't see that rock, or ugh I fell with the canoe.  Of course we're all susceptible to you gotta be kidding me the yoke broke or something even worse. 

Fingers crossed, with a hull issue, the tape will suffice to get me out of the park ok. Even if the yoke snapped, I would hope I could jerry-rig some wood sufficiently to tape across and get me out of the park.  Somebody posted some fantastic photos of a repair they had to do to a yoke this past year, don't remember whom.  The putty, the fiberglass, zip ties...to me, tape can serve as a substitute for those in nearly all cases.  Nuts, bolts, screws.....that stays at home for me.  Sometimes I check to make sure all is well before I leave from home. 

So, the question is what are your most likely damage possibilities, and what will suffice to get you out of the park.  That's as long as a field repair needs to last. 

Anyway, that's my recommendation.  Tape.  (Now watch you go have a serious problem for which tape is not the answer....)  We'll see what anyone else has to say, there are tons of people waaaaaay more experienced than me out there, that's for sure!

What I do carry with me (and it stays in the car) is an extra belly strap for the roof rack, and some extra paracord in case a tie-down line snaps.  A problem in transport like that can leave you sitting on the side of the road stuck.  Not even duct tape could solve that problem! 

Sounds like you have it pretty covered. Only thing I would recommend  is a partial roll of Blue Skin, peel and stick foundation sealer.  Works awesome.