I rode the CO trail on a Suzuki 200 DR with saddlebags and original tires. No problems below 12500 feet, above that there was a shortage of power. Some of the steep rocky sections would have been easier with a lower gear as I could have taken them slower. I even did Black Bear Pass.
I also rode the great divide mountain bike trail this summer on the 200, with same set-up.
I have just purchased DRZ400S getting it ready for a Copper Canyon trip.