I moved my flock 7 hours away twice - first to my daughter’s house and then 3 months later back home to mine. It was hens and one with several young chicks, also a few old girls. I didn’t have a roo at the time but don’t think that would have made a difference.
I fully expected to lose a few chickens from stress or illness due to stress but everyone survived both trips perfectly!
I used large dog crates which I had collected from people’s garbage! Not kidding. Of course this was over time. It’s not that hard to make a replacement door if needed. Screen cut to size and a bunch of zip ties work good enough.
Anyway, we did use a flat trailer. We put plywood low sides (no need for taller than the cages) around the sides nearest to the suv/hitch end. I thought the plywood plus the body of the car would help protect the cages. I don’t know if it made any difference and all survived fine but that’s what I did. I put the broody and chicks in one cage. All the others were split into cages where they had good space but not too much. Maybe 6-7 per cage? Depends on chicken size and cage size.
We did drive thru the night as I did feel that would be less stressful for them. Again, don’t know if it made a difference. I checked on them when we stopped for gas and food. They were fine - no craziness or fear behaviors. Frankly I was surprised and pleased on how well it all went!! The return trip we did the same. All chickens did great!
I did have generous straw in the cages. No food or water as they weren’t going to eat or drink anyway and less mess or chance of injury.
Ro unload we carried the cages into the new coop and opened the doors. Placed food and water a few feet away and let them come out as they wanted to.
The question I have is whom is taking care of the chickens at the new place while you’re back in OK?
I have traveled with many chickens in cages for a few hours with them in the car. Major stink!! Can’t imagine doing it for 7 hours.
Good luck!