Thank you, Eggs on Toast! Your wintertime temperatures are the same as some of our night time SUMMER temps, LOL! So, I'll have to keep thinking, but I love your little "quail box!" Is it secured into the ground in some way? In my area, predators would either flip that, or dig under it.
When we had Button quail living in the small dog actually dug and got under the cage and another time she dug a hole beside the cage just big enough so she could fit her head through and got one of the quails. So we put some rocks around the cage and then started building a fence around it to keep the dog out. I don't think we have many predators over here except from pets and wild birds so didn't need to do any major reinforcing. But I guess if I did get a lot of trouble with predators digging underneath it then I probably would put some wiring around it in the ground.