Build what you want, nothing mass produced works worth dang in anything much below 25 degrees. I'd start with a HD cargo trailer or a Featherlite aluminum trailer and build from there. Then you can control how its built , for example, I'd order 9' side wall and then build a false floor inside to put my tanks and such on, much better way to control the cold, stray foam insulation, dual pane windows, your AC and a furnace. Could be built on either a bumper pull or GN hitch. I'd look at air ride with the kind of off roading you do.
