I open the door and let the chickens decide. They have never stayed in. If weather is bad they prefer to sit under the bushes or in the raspberries so they can still eat and scratch.
1. my eggs last at least a month out on the counter.
2. my chickens came with cute little down jackets. (even covers their cute little bee-hinds)
I open the door for them every single day! Sometimes when the snow is heavy on the ground - the door gets opened a little later, cause I don't really like going out in it!