At night, how far away could you tell it is your spouse walking toward the door?
Impossible to say. The description says “up to 30 feet”. I will be doing some testing to confirm things, but suspect that while you may be able to detect motion out to that distance, the resolution of the image would not allow identification.
When the police are looking for a bank robber or holdup suspect they often show video from the businesses security cameras. Even in banks, who I would think would pay for the very best, the video quality is usually horrible. I suspect good night vision is much more difficult and expensive than most realize.