I wanted to test out the van for an overnight stay. The first thing on my list was getting another fan since one of the notes from sleeping in the Fit was to get better airlow so I got a 5-inch USB powered fan from Amazon in addition to my previous battery powered fan.
The airflow from the two small fans was enough to get through a night in Florida.
I put down some cardboard boxes and put my mattress topper folded in half on top of that (I folded it in half to have it around 30 inches wide to simulate the width I will probably end up having the final van setup) and covered that with a bed sheet.
I placed a blackout curtain with a rope through it (the one I used in the Fit) to cover the open parts of the bulkhead to block out any light.
Similar to the overnight stay in the Fit this was also a success. The bed width and length was sufficient and I actually underestimated how well both fans worked so I was a little chilly during the night.