Thank you all for the great suggestions. Now I have to undergo the suspense of waiting to see if there are still rooms availble at my top choices after SPG announces their promotion (if any) covering September...
As I've conducted my search, it has dawned on me that what I really am looking for is a cozy country inn in a smallish, quaint French town, and with a really great dining room (and chef to match!) where they open the french doors to the outside and let the sunset stream in on warm evenings - but of course I want to find this in Paris.
Oh well, I can dream, can't I?
As I have had more occasions to visit France, I've begun to be torn between whether to spend more time in Paris or focus more on the countryside. I think I may have just reached my tipping point toward the smaller country towns, even though that's impractical for this September.
In searching for a hotel this September, it has surprised me a little to find quite a few pockets in Paris where there are essentially no hotels. I had initially figured on could find a hotel on just about every block. I'm not sure why I thought that, but it turns out not to be the case. Most surprising, and disappointing to me is that there seem to be no hotels fronting the Canal St. Martin, despite having read about the desirability of living in that area.