How do you keep rabbits cool in hot climates?

Soon I'll be adding meat rabbits to my tiny pseudo farm. I live in west Texas, where winters are short, the wind can be strong, and temperatures don't get below 90 all summer. We regularly get over 100. Naturally, heat is a major concern. I've done research, but every piece of advice is something like "put them under trees". Have they ever seen the desert?

I have to build an entirely new structure for them and they can't come in the house except for maybe rare extreme conditions. My current plan is to erect an open-sided wood framework with a corrugated plastic roof spray painted white to reflect the sun. The sides will be protected from intruders with some kind of wire "walls". The roof will extend several feet over the cages on each side to provide shade. I'm thinking about making the west wall solid plywood to keep the afternoon sun from hitting them directly.

During the summer I'll have two or three large coke bottles or milk jugs per rabbit, prefrozen with backups to change them out as needed throughout the day. Each cage will have two large water bottles, checked changed and refilled if needed when the ice jugs are switched out. Since they'll be in wire bottomed cages, part of the cage floor will be covered with ceramic tile. This should provide a nice resting place and keep from hurting their feet.

In extreme conditions I could run an extension cord out and hang a fan, but if there are better ways I'd prefer that. Does anyone have any advice or experience in this? I can't put the setup right next to the house and again, there are no trees.