Infrared is the feature most often oversold on the spec sheet and most often disappointing in the timeline. Understanding four of its properties will save you a redesign.
First, IR is monochrome by definition. The illuminator emits near-infrared and the sensor drops its IR-cut filter to see it, which means every color descriptor you would put in an incident report disappears.
That matters more than the loss of fine detail. A grey sedan and a red sedan are the same sedan at night, and a blue jacket becomes a mid-grey jacket that matches half the wardrobes in the county.
Second, IR obeys the inverse-square law. Double the distance to your subject and the illumination reaching them drops to roughly a quarter, which is why a published IR range describes the distance at which the camera still sees something rather than the distance at which it still identifies anyone.
Your practical identification range at night is always shorter than your daylight range on the same camera. Plan around the night number and treat the daylight number as headroom.
Third, low light forces the shutter open longer. To gather enough photons the camera slows its exposure, and a person walking at normal pace smears across the frame exactly when you most need their face.
This is the failure that surprises people, because the static scene looks fine. A parked car, an empty walkway, and a closed door all render sharply under IR, and the one moving object in the frame is the one that blurs.
Fourth, IR washout is the most preventable problem on this list. When the illuminator hits a nearby wall, soffit, railing, gutter, or a spider web strung across the lens hood, that surface returns a bright reflection, auto-exposure compensates downward, and the rest of the scene goes grey.
Accordingly, get the lens out past the surfaces around it. Use a standoff or arm mount rather than recessing a camera into an eave, keep the first several feet of the view clear of hard surfaces, and check the housing seasonally, since spiders are drawn to the insects that IR attracts.
Weather amplifies all of it. Rain, snow, and fog reflect IR straight back into the sensor the way high beams reflect back in fog, and a scene that is clean in dry conditions can white out during the storm you actually needed to record.
The reliable fix is white light. A porch fixture, a soffit light on a photocell, or a PoE floodlight keeps the camera in color mode, keeps the shutter fast enough to freeze a walking subject, and preserves the clothing and vehicle colors that make a description usable.
Remember that the goal at night is a small area lit well enough that the camera never leaves color mode in the one place you care about. Pushing IR further into the dark buys far less than that.