I've begun moving the cages to an improved location; much more brief and indirect sunlight in the morning, and only a couple hours of sunlight in the early evening, when it won't be as hot. Their tarps will be moved also, providing a nice temporary roof and windbreak.
Phase 1: get all cages & rabbits back home and settled (this was done Wednesday 3rd).
Phase 2: move all cages to a more sheltered, shaded area (begun Sunday, completed Monday).
Phase 3: cover all cages with tarps, to provide windbreak, and protection from sun & rain (to be done Tuesday) - for now, they've all got temporary sun shelters to keep them cool where they're at.