LT preferred temps will be about 9-11C if you're planning on trolling near shore... brook trout temps will be a little higher so if the water temps don't cool off sufficiently, BT might be a better bet.

I'd simple troll near shore, covering as much distance as possible, and if you do catch one there may be others in the same area. Good luck, I've seen some pretty nice BT caught near the end of the season.

I've had good luck with lakers trolling rapellas in blueish color ... not sure why but I know I'm not the only one to mention it. If you get one take note and cover the area a few times in case they are schooling a bit. 

Agree that brookies would be easier ... I tend to pick a diver that will go in the 8 foot range that's about 3 inches so that it will attract brookies or lakers. 

You could also try jigging while drifting with the wind with jigs or spoons with a piece of worm on the tip. Really anything that will get you deep - probably between 10 and 30 feet depending upon water temperatures.  It's easy to do that with a jig (deer hair, twister) as the wind gradually pushes you.  Wind speed will determine how much line you need to let out to be deep enough.  It's surprising how a little wind can move a canoe - adjust your speed with a few paddle strokes here or there to speed up or slow down.

We've found the best luck around steep drop-offs near shallower water (i.e. a point of land or island jutting out into deeper water).  The trout can hang deep but move up to shallower water briefly to feed around the shoal.