I know things go bump in the night and nothing is perfect. Forest River takes effort to market their insulation ratings and how the foil barrier is installed top and bottom. However when I went into a unit on a sales lot this week in Florida with temps around 90, I stuck my head in the pass-through storage and it was chilly in there.
Knowing something ain't right, I asked the sales guy if the basement was supposed to be cooled and he quietly said "there may be an issue with that unit." My point is that RVs in general are never a sealed box as your home may be. If you have any suspicions that is may get hot inside IT WILL. If you ever have a chance to upgrade A/C when making a purchase DO IT.
Now if you're the type that only camps in the mountains, all of this applies in reverse--get more heating capability.