Best advice I can offer is don't feel any pressure to drive the speed limit. Drive for the conditions and for the love of your RV.
Hubby hates rattling the fifth wheel around so he cruises along at about 40 mph, on occasion up to 50 mph. On the 120 miles between Destruction Bay & Beaver Creek, we plan for a four hour drive. The road is too unpredictable. On one of our trips (we often visit Beaver Creek because it is my hometown), we travelled behind motorcyclists also driving at 30 mph. One of them had hit a huge pothole and damaged his bike, so they were taking their time.
If someone whips up behind us, we simply pull over and let them pass.
In my little car, I'll whip along at 70 mph. BUT I know the road and it brakes in a short distance, and swerves exceptionally well.