I ride those roads all the time, it should be awesome. The Peak to Peak highway is gorgeous, and the pavement on the St. Vrain descent is silky-smooth. Bring your low gears for the last mile up to Ward.
I would be doing it, but I'll be starting my 3 week bike tour that day, so if you see 3 dudes and a chick (me, duh) riding up the St. Vrain or heading out towards Estes Park on fully loaded tour bikes, wave!