Not being sarcastic but, IMHO I really would think if someone was spending the money for a big diesel pusher or a pickup truck and big 5'er that they would know how to operate it in any conditions and roads. I mean there are some big mountain roads with switchbacks but if driven correctly are no problem at all.
Now, if a person buys a big RV and thinks they are still driving the car like they would to Wal Mart they should probably stay in the Florida area or get some know how before hitting the open road. I drove big trucks all through the mountain west for many years and one thing is for certain, you need to know how to do it before you get there !! Free wheeling down a steep grade with hot brakes is no time to learn how to drive in the mountains. Use your gears even with an exhaust brake, stay slow, don't get going so fast that now you can't slow down and last but not least.... use all the common sense you have !! .