Sounds great to me.  8-)

Been to most of those lakes, nice areas and plenty of dandy campsites as well.

I did a 21-day solo a few years back and found the limit to how much food I could haul was about that amount of time.

I don't pack light food wise so if I wanted to go to all freeze dried I could go longer, but I like to eat well so 3 weeks would be about right for just me.

That extra paddler/portager really extends your range. It should a trip you'll both remember for a lifetime.