When my two kids were young, way back in the unsafe mid-1980’s, I’d set up my 1986 Caravan for week long camping trips (BTW I did the same for my 1991 and 1998 Caravans). What I did was make a 4’X6’ platform using 1”X12” planks for the sides and 3 removable 2’X4’ sheets of plywood covered with carpet for the top of the platform. The platform top was supported in the middle by 2-2”X4” wood cross beams. The sides and cross beams were held in place by screws and angle iron braces so that it could all be taken apart and stored in the garage attic when not in use.
This platform had great storage underneath for gear/clothing storage and with sleeping pads the kids had a nice safe place to sleep. I’d usually sleep outside in a tent unless it was raining really bad and then we’d all crowd into the Caravan. While traveling the kids could play or rest in back. Of course this was before all the current child safety laws were passed. I often wondered how anyone of us ever survived childhood back then!
Steve