My girls went through the winter in a 10' x 20' chain-link enclosure. We got the panels on CL. We ran hardware cloth around the perimeter and either down a trench or out as an apron. That covers all the connecting gaps except part of where the door hinges. We topped the whole thing with a 10' x 20' tent from CostCo (about $200). So far the tent is the only protection we have up top, but since the flying predators cannot see through it, it's worked so far.
Advantages: quick to set up, I can walk in there upright and the girls can spread their wings, I can hook stuff to the walls, tent top keeps out the rain & snow, and tent sides can be lowered in cold weather. You can padlock the latch.
Disadvantages: Cost, unless you get a deal or have some laying around, snow load can bring the tent down unless you keep on top of it (and would be a threat to a wire roof too).h