Saw this a bit late.

I rode the Divide Ride with just 2 front panniers and a dry bag on the rear rack on a rigid 700c wheeled bike with 45mm tires. I had no mechanical problems except for one flat tire due mostly to going light weight.

I met many riders there who followed the Adventure Cycling advice to use a trailer and a suspensed mountain bike. Many were overloading their BOB trailers and had rear wheel problems on their bikes-spoke breakage and rim fractures. Some had handling problems particularly going downhill. Watching them push their bike and trailer up passes was painful to see.

My lighter gear load allowed me to ride what they walked and pushed. Less is more in this case I think!