Calisdad, the "climb over" aspect of a really small trailer is not so bad, if your knees and arms can deal with the effort. Before you throw it out of bed (so to speak), give it a try at home.
The way we've arranged it, DW sleeps on the side of the bed toward the bathroom. So I am the one who has to do the climbing, being careful not to injure her. (I weigh 230, she weighs half of that!) . I do not mind this task at all.
Plus, there is a way to minimize the climbing -- when she visits the restroom in the middle of the night, I get up after she does. No climbing. She then goes back to bed. I then climb over her in order to get back into bed.
In a perfect world, we would have a walk around bed. But having a tiny trailer means that it can fit on our driveway. It is easy to heat -- our bodies practically do the job without the furnace, except in sub-freezing temps. A little trailer is easy to tow, easy to get into gas stations and parking places.
And with proper modifications (leaf springs, shocks, big tires), we can get the trailer into almost anything that a truck camper can handle. Not quite, but really close. Steep, rocky forest roads are no problem.
But MPG is not much better than a bigger trailer. Same wind resistance.