I don't think in terms of "distance". It's a "red light/green light" kind of deal for me.
I once passed on a nice bull elk that turned out to be under 20 yards and have center punched a mule deer buck at what later gps'd to be 37 yards. Some times it just doesn't "feel right". Other times you just know it's a dead animal walking. Animal posture, lighting, and my general sense of focus all come into play in determining what trips the light.
I passed on my dream bear last spring after an hour long stalk because the light never went green. He was under 25 yards a few times, but he was always at off-angles, and moving enough or me to not be able to hold a steady focal point on him. In the end i spent 15 minutes in what would normally be "dead bear range", but he walked off.
Later in the fall, i smacked a ruffed grouse off of a log at 49 loooong paces,and i knew he was dead before i drew my bow.
FWIW, i shoot regularly all year around at distances out to 80 yards (mostly roving), so my shot indicator system is always in calibration mode.