I am retired, but mostly when it comes to canoe trips I am just tired. I can't imagine doing 47 days. If you really want to do some long trips consider doing them sooner rather than later.
I am likewise retired, and when it comes to canoes trips am in some ways tired as well. I have largely given up group trips (largely, I have one coming up in October). I trip more solo, or with a selected companion or two. I trip more slowly and gently. And, with anything approximating a long hard portage behind me, more comfortably.
I don’t see a long NFCT in my future, especially not the upstream parts, but given the right venue and companion (or not) I am still in my ease with multi-week paddling trips.
That may be because, on trips remote from home, the net has made it much easier to gather information not just about paddling venues, but also about strange, peculiar and unique places along the way, from freebie campsites in Nat’l Parks and Monuments to little visited wilderness areas, Wildlife Refuges and dirt road wonders.
And, if you can find your way to those special places, many folks you encounter there off the beaten path are kindred spirits, and are often willing to reveal their special places along your route, especially if you return the favor.
I’ve got a couple of paddling road trips in the next month and can’t wait to get out and see what I find.