NRO talked to Missoula County on the phone. They are going to grade some pothole sections on the course. I will for sure ride the course two more times and report back on conditions.
There have been a few Roubaixs in recent history where the road had been graded. It can be rocky. Pinch flats and flying rocks can be a problem on all the descents.
If you are on the fence about which bike to ride, give it a few more days. I will provide a full report with photos if the road gets graded.