I got a good deal on a Bags Connection Racepack and tried it on the Griso. It may not be anyone's first choice, but it does provide a lot of space that is not broken up between saddlebags. It goes on and off easily. NOTE: I did eventually strap it onto the bike (pictures were taken with it resting on the seat). I strapped the back to the spools under the seat and the front to the rear peg hangers. Its stable, reportedly waterproof, and expands to carry even more stuff. Most times though, I just ride with a backpack as I don't need to carry much stuff.
Anyways, some pictures for an alternative solution. I do like the looks of the MG saddlebags and the HB C-bow bags and mounts. But will try the Racepack for now.