Nice coop!
I'd put a nightlight in the coop that will draw them up and into the coop at night as they will follow the light. A couple of 2x4's to put across the narrow width, each at the same height but about 3-feet away from each other will offer ample roosting space and discourage squabbles over choice spots. I'd ensure that the food and water is not under the roosts, and I'd attach high quality, rubber bungie cords to them to enable you to lift them out of the reach of rats and mice at night simply by repositioning the bungie. The rubber bungies will last you years and years, the colorful wrapped type bungies may only last a year or two; for the price difference, my money is with the rubber ones. You may also consider buying a few sheets of zinc roofing to form a wind break on two adjoining sides of the run to block your prevailing wintertime winds. Looking at the image of your coop again, you might be able to get away with only covering the right hand side (as you're looking into the coop from the doorway), as the coop structure may provide enough of a wind break on the far side. The roofing is typically inexpensive, incredibly sturdy, won't rot, resists rust, is termite proof, and snow slides right off. Again, financially speaking, I believe zinc roofing is a better value than fiberglass or steel, as zinc's natural oxidation process mends minor nicks and scratches without any effort on your part. You can punch holes along the edges of the roofing with a nail or ice pick and attach it to the current structure with sturdy zip ties (black ones if you can find them at a good price). If you elect to leave this up over the summer, it will provide deep shade as well, but will probably need to have the zip ties replaced, or at least inspected, after summer has ended.
