Jaximus,
I'd say the 15l# PP would be about right, although as you can see the line weight runs up or down depending on who's using it.
I'm a solo paddler, so when I'm traveling and have a line in the water,
which is 90% of the time, weather permitting, I use the 20# PP on a Med-Heavy UglyStik rod.
I used too lose a lot of baits because by the time I could grab rod or stop forward momentum solo, a lighter line would snap under the pressure.
I found with heavier test, I can set the drag right, and unless I'm being pushed by a good tailwind, I don't break off as much.
20# PP is about 6# mono, so the lure gets down well, and I don't think it's costing me missed strikes, although with the quality of fishing, I don't know how you would even know that

If I was in a tandem canoe, I'd probably go lighter as you have someone to control canoe and more time to monitor your rod.
I have 2 spools for my 2 spinning rigs I bring, with a mix of braid and mono ( TECTAN). If you've never used this premium German mono, give it a try if you can find it? Cabelas carries it or used to. Ultra-thin, ultra strong knot strength.
I use the 11# Tectan, which is about regular 4# mono diameter. On a light spinning rod it's great for smallies/Waldo's and will handle the big boys with a little extra backup if needed.