i'd wait until the next day. i did it this past year tracking for my dad. he shot a deer he was certain he'd hit well, but we couldn't find any blood. i took off the next day, and found it about 300 yards from his stand, never saw any blood, just where he was dragging his feet in the mud and leaves. when i got up on him, i found that my dad's broadhead had shattered when it came into contact with a rib bone. when he finally bedded down it looked like a murder scene. i'd have never found him in the dark, but wasn't going to let him have been shot in vain. so yeah go as long as you can that night, and then go the next day.