I have been doing outdoor video since about 2001. I started out with Sony CRT projectors and finally graduated to DLP with about 1200 lumins. Today you can do much better, but I am sticking to my 10 year old Mitsubishi HD1000 unit because I ruggedized it to use outdoors.
I have had various configurations involving front and rear screens, using the projector hanging from a 18x20 carport canopy for stage performances and on the ground for smaller gatherings.
I have tried projecting from inside the motorhome, but reflections off windows and angles were always a problem. The throw of my projector was not very good for a decent sized image with a screen at the end of the awning.
I have simplified my setup using a 10x10 popup canopy with a stretchy screen tied to one side with bungees that works for front and rear projection at the same time. Unless there is text, nobody notices.
I put the projector on a milk crate under a table under my awning to keep it out of the weather. The HDMI cable runs through the window to a video splitter from the Oykyo AV receiver and inside TV.
I have stereo outdoor speakers wired from the AV system on long enough extensions to reach the sides of the screen.
What I dont have is a good photo of my setup, but this one from FB shows the 10x10 popup at the rear of the MH, the screen is swung up for daytime use of the popup. The projector is under the pile of tarps to the rear of the entry door. The speakers have been moved to the arms of my awning.
When I go all out I bring a 10' diagonal outdoor screen and pro speakers with over 1000 watts of power.
My fans like my Pink Floyd Darkside of the Moon and Wizard Of Oz mix out in the middle of the woods.