Hi Pannell,
Welcome to the Heartland Owners Forum and to the family. We have a great bunch of people here with lots of information and all willing to share their knowledge if needed
There was a thread about this a couple of weeks back also,,, you might do a search for it... But I "think" (shouldn't do most of the time),, they were more concerned with the flex of the walls and everything while towing more than temps. I "think" that someone suggested that you use your sink covers for that when your parked... you need a place to store them anyway. Like I said you might want to search the forum.
But with the Heartland family, you can be sure someone will come up with an idea or solution.
Enjoy the forum and when you go for PDI,,, be sure and do a really through inspection.
Jim M