Thanks for the advice Bruce.
I had been considering putting a drawer or locker under the fridge to raise its height for less bending to reach items inside. Instead, I will go back to my original plan and vent as you have shown.
I find that a small fan works reasonably well for improving airflow in warm weather in our Airstream. To my surprise, the airflow that works best is downward. I'll make sure I have enough space to add a fan in the future if necessary.
This trailer is designed for just one person. Even so, my wife and I are not uncomfortable on a bed only 39 inches wide as we are both smaller folk (well, I'm not nearly as small as she). Our Westfalia had a width about this size and it was never a problem for us.
Never say never, but resale is not an issue for me. I'd rather not compromise my vision for "Where or When." If I should chose to sell, I only have to find one buyer.