Winnebago's are checked at 85 PSI at the factory. I had my regulator set at 65 PSI According to Winnebago that is fine. I spent a couple of summers with the unregulated pressure at over 120 PSI and the 65 PSI caused no problems.
Most household appliances are rated to 85 PSI - a few like my Samsung ice-maker. are more. I don't remember exactly what the specs said but as I recall it was over 100 PSI.
The water pressure here where our house is 135 PSI. The whole house Watts regulator was set at 65 PSI by the tech when he replaced the old Watts that had failed before we bought the house.
The old one was installed in 1999 and the rebuild kit for it is no longer available.