Isn't High Mileage Still a Problem on DP's

Having driven Coaches with over a million miles on them but yet to purchase a DP. My concern is those that head south for the winter in Nov, sit until April, then head North to sit April until Nov. Granted they have low mileage, but they have been lived in constantly. The appliances, roof with potential leaks, rust, and the break down/age of the furniture matter. I have driven and seen diesels with well over a million miles, with good maintenance this is the norm, not the exception. It's everything else that concerns me. Just something to think about, colors and fashion will change before that well maintained diesel will give up.