[ahmm]

The Sault to Subdury takes roughly three hours by car. You'll have a good choice of hotels in each location.
There will also be places to stop along the way if you decide you need a break sooner.

I'm envious that you'll be travelling through Ontario in September. It is beautiful in the fall.

This website might help you decide the course you'd like to take:
<!-- m --><a class="postlink" href="http://www.ontariotravel.net/TCISSegmentsWeb/gc/FD?language=en&_nfpb=true&_nfls=false">http://www.ontariotravel.net/TCISSegmen ... nfls=false</a><!-- m -->

Enjoy!