Yes, we had that same problem with our 35ft 5ver, we had to install a 2nd A/C in the bedroom. The 15 BTU wouldn't cool the bedroom down, but that was mainly an air flow problem.
So that is why we are really concerned about the 13.5 unit. There are two options, 1 - 15,000 btu'son 30 Amp or 2nd A/C in bedroom and 50 amp upgrade.
We don't want to run into that problem again, traveling in the summer can be brutal, and going out west means spending a week in Texas. (LOL, not quite, but it seems like it)
Thanks