No, one camera will not do both, especially at night. And that thread you linked isn't indicating that - that person wanted to know if a PTZ with the larger zoom could be set up to read plates, but that is all it will do in his setup.
You have to decide do you want the zoom capabilities of the PTZ to read plates or capture people/vehicles.
It will not do both at night. During the day it can probably do double duty, but not at night.
Some people can do both under ideal situations - like at a stop sign and a lot of white light like
@Flintstone61 showed above, but that is the exception. Based on what you said, I do not think you have enough light.
I suggest you read the LPR subforum I linked and look at all of the examples.
Shutter speed is what captures fast moving objects. The faster the shutter, the darker the image. At a 1/2,000 shutter, the image will be black except for the reflective plate and head/tail lights.
By contrast, you will run the shutter of the PTZ to capture people somewhere around 1/30 to 1/60, but at that speed, the plate will be white.
Here is what the plate will look like if the camera is setup to get people at night:
Here is someone walking past my LPR camera in the middle of the night with a reflective vest on. As you can see, all you see is the reflective stripes. Had he not been wearing that, the camera wouldn't even have picked him up.
The
5241E-Z12E is the go to camera to set up to read plates. Keep in mind this is to allow you to manually read the plate, the camera does not automatically read the plates. You would have to go double/triple the price to do that, but those cameras do not have a large enough zoom. This camera can get 150-175 feet or so before you need additional infrared.