I have never heard of warming the roosting area. How do you do that?
Chickens hate change, but it goes both ways, once they get used to the coop, they will tend to stay there, generally speaking.
A long handled sorting stick, or even a branch can be quite helpful to rounding them up in the late afternoon, but you need to do it very slowly and quietly. First put a tiny bit of feed just inside the gate, and bigger pile of scratch farther in. With the stick that is long enough you can easily tap the ground, go out around the flock so that the flock is in between you and the coop/run. Walk towards the flock with the stick out to your side, tapping the ground and quietly saying "hut, hut" Walk forward until your birds start to move away from you. They should not be running,flying or upset, just stepping away from you toward the coop, still mostly pecking the ground. Once they begin to move, you stop. When they stop then slowly you repeat saying "hut, hut" tapping the ground and stepping forward until they move again. Repeat until they get close enough to see the food.
Now one may duck past you, leave that bird, the natural instinct is to stay with the flock, and while skittish, they will be quick to get in afterwards. This technique will get the birds close enough to see the feed, the first ones there will get excited about the treat, and that will bring the others. Once most of the flock is in the fence, you have some time to go get the straggler. Again, just get out around that bird, so that the flock is calling on one side, and you are applying slight pressure to go towards the flock.
You can actually round up quite a fair size flock, in a relatively short time period, without the chickens really aware that you did it. But you need to be slow and quiet.
Mrs K