I suggest the PUGS for the bunk ends and Reflectix (can buy at Home Depot or Lowes) for the zip down windows and for under the mattresses.
The PUGS will give you another layer of protecting from the sun beating down on the canvas, plus it will keep the inside significantly cooler because it reflects the suns rays, plus the added benefit of blocking light as well for a better sleep. Don't know if it will help insulate the insides during cold weather.
The Reflectix has roughly the same principles.
We just got back from Florida and my wife was constantly saying that it was too cold inside the camper