Thanks for the comments.  I have used "true" solo boats and I know that is probably the best way to go, but I'd like to save $30/day.
My Northwind has the wood trim option, so to put a seat where I am thinking only requires drilling 2 additional holes, both through the wood inner rail.  I would use the existing thwart holes for the others.  It seems like a prudent option.  There is even a narrower (looks like 4" versus 8" at the seats) piece of structural foam in that position of the hull sides.
As far as handling, I paddled with my 2 boys last summer on some big lakes in a strong wind.  They are not strong paddlers so I know what it would be like to paddle it from the stern solo.  And I know the boat will be riding higher with just me, but that is why I like moving myself closer to midships.  The canoe should be much easier to handle solo from closer to the middle.
I think I will go ahead and give it a try in the next few weeks or so on one of the local lakes and see how it does.  I'm pretty good with wood, so I will try to make my own canted seat supports based on the existing ones and a solid slab board seat for the trial.  If I like it I will see if the bow seat fits and use it or get another cane seat to use.
Now, if I had the $$$ I would buy a solo canoe, that would make 3 in the house, and it would be a Stewart River Traveler.  :)