I am currently using the tripod/tarp idea, pics can be provided later if anyone can remind my forgetful butt... lol
few things i learned quickly:
you need cross bracing on all three sides, not just the one.... which makes moving them something that is done simply by picking the whole tripod up, rather than collapsing the tripod and moving it flat. But this is nessacary for stability.
in one leg of each of the tripods i had to drill a half inch hole so i can drive a rebar stake into the ground, otherwise the wind pulls the tripods over. ( when you move the tripod you simply lift it off the stake, the stake comes out easily if you use a small pipe wrench, turn the stake three times and on the fourth turn lift with the pipe wrench... comes right out.) My stakes are approximately 18inches and i drive them just deep enough that they are not a tripping hazard for the ewes or the lambs
That tarp is not going to last very long in our environment unfortunately but for now it is working. One thought I had, is rather than tying the tarp to the tripods, have it permanently attached to two poles on the long sides, then rest those poles on the tripods and utilize weights if needed, that way the tarp flaps less and has some rigid support.
I use 4 tripods and a square tarp.
Tripods do not have to be overly large, I cut my poles down from 11.5ft to 7ft and that seems a good size, 6ft may be sufficient and weigh slightly less.
I think I would still like to eventually mount 4 bicycle tires to my sheep shelter I built last year and just roll that along, skids or using two small tires on the back proved to be too damn heavy last year and these tripods are thus far an improvement.