Good morning, Boe,
You don't say which book -- there are four -- but from your question I can tell it is not Striper Surf so it must be TROPHY. I have no first hand knowledge where they winter but books say a large group is off North Carolina in winter. Total speculation on my part, I'll guess that much of what we fish for is broken up into contingents sitting here and there. Not in suspended animation but at reduced level of activity to preserve energy. Deer do that and I think much of what we have in nature resorts to similar means of dealing with their respective enviros. Atlantic salmon also.
As for senses, humans would all be more effective food gatherers if they stopped looking at their quarry in human terms. Wildlife is capable of responding to many more stimuli than we are. For instance, ever watch how a suspicious deer raises the alarm, or gets ready, by raising its foot. It is not smelling, calling, listening, but it is employing vibration. Other than the beach boys, what humans utilize vibration? You no doubt are referring to "proximity sense" which is something I gave rise to in one of the books (1/4 million words with four, so I don't remember.) This is the total of all a lineside's senses which as yet are not understood. I had to resort to this somewhat vicarious label to explain how a bass, she could, (her come the Cadien)lay in a current with a full tide drop like the Boston girls got the tow rope, darker than a swamp bottom, cloud cover, and see your swinging jig in 12 feet of water and never miss. Now there is an animal that she hunt, like a full belly would be not too shabby. That is proximity, a knowledge of where the forage it be.
Good question. Hope you don't mind the fun, ma man.