The door should be covered from the inside, where you can better control the lighting. WDR should be used of course. The camera should be, as you said, roughly 10-15 feet away, looking at/through the door.
If you also want the outside covered, add an exterior camera or two as overview cameras. They don't need to be tight shots, you will have a great identifying shot on the door from the inside.
The reason why you don't cover the door from the outside is you can not be assured that the subject will walk directly through your scene. They could hug the wall, or come from a blind spot. Unless you have a multi-imager, you cannot be assured to get the identifying shot needed. Usually there aren't pinch points outside that are better than the doorway itself. If you have the camera right above the door on the outside, looking straight down, you won't have a decent facial image. If you have it pointed outward at a normal angle, you will likely have a blind spot directly below the camera.
Another reason, the indoor camera is harder to tamper with before being seen by it already. An outdoor camera has a chance of being sprayed, shot, etc from a distance. I know this is an extreme example, but still a consideration to be thought of.