Phil, great idea! You are exactly right -- the awning poles can be swung down into what the manufacturer calls "carport position," although it would have to be a very small car. ;)
But yes, I could anchor the trailer's awning poles to the ground -- then tie one end of the center rope to a bridle around those poles -- and then rig up an inverted "V" to support the other end of that rope, using a guy wire to apply outward tension to the top vertex of the V. I would then anchor the guy wire to a stake driven into the ground at an angle.
With the "diamond" pattern described above, I won't need to support the two corners of the tarp -- the tarp is stretched diagonally over the center rope, and the two triangular flaps extend out to the sides for drainage. Those flaps will also be guyed out to stakes on the sides.
I think this is going to work! I gotta try this out, the next time we go camping in the winter. You can bet there will be pictures and a report.
