I've been thinking the same thoughts about doing a trailer. In a perfect world I'd buy a Timberline Camp Legend, but price is around $24K, and weight is 3500-lbs. I'd like to cut price and weight. Looking at a cargo trailer, price for a 6x12 is around $3500, and weight around 1200-lbs. one company I spoke with said I could upgrade with taller tires (off-road), thicker plywood, insulated, better roof support (snow load), plus windows, etc.
I would then add wood burner stove, solar panels, battery plant, inverter, bunk beds, etc.

Next week, I'll be in Montrose, and I'll look at some travel trailers for ideas.