We can probably do two weeks on the trail for something like this.
That's about what I usually plan for although I have yet to find a "favorite" and next summer's will likely be longer.
My long trips since joining this site:
My
BWCA route was awesome and, while somewhat remote, had the security of feeling that help wasn't completely unavailable. Amenities such as thunderboxes & fire grates were at all sites. Robert Beymer has written some
excellent books with route suggestions and you'll probably find
paddleplanner helpful to combine routes as few of Beymer's suggestions are more than 3-5 days.
(Paddleplanner also has info on other parks like WCPP, Algonquin, the Everglades and Wabakimi but the amount of info available varies widely depending on how many people volunteer their efforts to post pictures and campsite/portage info; especially since they've gone more pay-to-use-it than they did previously. Still a good resource though... even in free mode)
The
Steel River was great! Awesome scenery, good fishing, the river would have been lots of fun with more water and the portages were challenging as were Cairngorm & Steel lakes (obviously varies with wind). You could increase the challenge by taking on the Diablo portage if you want the "street cred" (I've been told it's worth doing once) and, if beginning the trip on Santoy, I probably would.
Here too, thunderboxes existed at almost every site although they were plywood instead of fiberglass and some were sketchy. There was usually a fire grate somewhere around camp if you needed it but the camps and portages showed much less evidence of being used.
For me, the most likely to get a do-over is the
Marshall lake loop simply because of the excellent fishing and the solitude. I really think I could have been out there for 2+ weeks and seen nobody until I reached the last few lakes. Fishing was terrific though scenery wasn't as varied as the BWCA or the Steel and some of the ports will test your mettle (and, perhaps, your marriage).
I saw no evidence of thunderboxes on that route and the only amenity on most sites was the firepit. Portages & campsites showed very little evidence of being used although there was a bit more garbage along the route than the aforementioned 2 routes. The last 2 portages, in particular, are pretty taxing. I'm not sure whether the two, combined, are as bad as Diablo since I avoided it but
@memaquay could speak to that as he's done all of them more times than (probably) anyone.
He can also provide some excellent maps.
I totally agree with scoutergriz above. Get the kids out early but maybe the ADKs, BWCA or similar until they're old enough to walk portage trails.
Whatever you choose, keep us updated.