maxxbhp: "If we're talking about a day trip, single portage, you could be in Ottertrack in a very short time."
Absolutely. You can cover more miles than you think if you're day tripping.
As for fishing for lakers, I finally figured it out a couple years ago after reading plenty of old threads here at BWCA.com. I shall summarize. I am an amateur, generally a horrible fisherman, and I had never caught a lake trout in my life before May of 2016.
Type "Lake Trout Fishing"
here to start. I like to troll a keel weight with a swivel followed by a rod's length of fluorocarbon terminating at a big, shiny, lightweight spoon. In mid June, I would fish where the lake is between 30' and Infinity' deep. I would expect to catch fish with the lure between 20' and 60' deep. Vary lure depth by changing the weight and the amount of line you let out. With a heavy weight on most strikes will be barely noticeable and the fish might feel like dead weight until it decides to make a run which might start within a few feet of the canoe. Hopefully you set the hook at some point.
If you type "Lake Trout Saganaga" in the above link,
this short thread is the first result and well worth reading. There are many more results, as well. Sag should have exponentially more lake trout of much larger size than Rabbit.
However,
Rabbit should be immensely easier to fish, given it has one hole and a total of 104 acres.
I bet you've really slammed the walleyes and bass on Sag over the years. Don't expect to get that kind of action with lake trout. The fish are down there. You might be doing everything right, just be patient.
Even if you take extra care, catching and releasing lake trout is much more hazardous to the fish than it is to walleye or bass considering the temperature and pressure changes the fish must endure. In the summertime I choose to stop fishing after catching a meal. I love my ultralight rod with 6# but a heavier setup will result in shorter fights and greater survival for the larger fish.
Sounds like you might enjoy leaving two thirds of your gear at home and paddling a loop one of these years. Enjoy your day trip this year, I hope you catch your first laker.