In asking around elsewhere, here was someone's advice:
Build an aluminum drain pan to fit under it, and plumb it for a fitting on the bottom, 1/2" would do. Mount the a/c unit 4" away from the wall, and make a box to cover the top and sides, between the unit and the wall. Cut an opening in the floor, as close to the size of the a/c unit as possible width wise, and as close as possible to the area between the unit and the wall. Basically this will allow the airflow from the condenser fan to come out of the back and escape
down under the r/v. The drip pan will catch condensation, and let it drain through the fitting to the outside. Assist fans shouldn't be needed, unless the opening can't be made large enough. If you do need assist fans, make sure the a/c unit is tilted and the drain located well away from the fans. The operation of the unit will tell you if the fans are needed.
It would likely work much better if you do cut a hole in side, and make a grate from expanded metal, with a filter installed. This would give the appearance of a factory installation, and reduce noise, both inside and out.
And good luck!
(((So, as this sounds doable yet difficult, will explore putting it under the gaucho with a side hole)
someone mentioned under the gaucho as a position for an AC -- I think they said "squirrel" fans or something were used to assist, and cutting a hole in the floor not the side, but these terms aren't not coming up on search
if this is so, it would really help to see a schematic of how this is done