I have 33K plus on my 2011, AC quit at 3 year mark, end of Ford warranty. Had Ford dealer check and they recharged and stated could not find leak, using dye. This was at 28K, have put over 5k on here since and ac is working as good as it can. Definitely will not cool entire coach but comfortable for my bride and I up front. When I stop for lunch or leg break, I start Gen and open the large vent on AC to dump cool air into front cabin. Hope this helps.
Logic will carry you from point A to point B. Imagination will carry you everywhere. "Albert Einstein". 2011 Georgetown 360, Bride of 45yrs, and 2014 Chev Equinox toad, what more could you ask for.