From those photos, at that age, and with those temperatures I'd move them out now as long as the coop is ready and it has good ventilation but also good breeze protection down low where they will be. If you were talking about below freezing I'd probably suggest acclimating them some but the way they are feathered out they can handle those temperatures.
There is nothing wrong with taking a slow and more cautious approach. It won't hurt them, just means more work for you.
Those are feathered out really nicely. What have you been feeding them, a really high protein feed?