Great info Andy...I'm sure it varies by watershed.
Its been awhile since I've floated the Huzzah in the winter but you can see bottom in 10' of water easilly...and you rarely see any fish. That creek flows pretty fast, lacks deep boulder habitat, and it doesnt have any major springs on it. So that might have something to do with it. There is lots of slow flow, spring seeps, and deep big boulder habitat on the Meramec though.
Think the situation might be different on Shoal...I've never visitied...but I've thought about it and done some research...There are tons of springs on the Shoal Creek drainage, plus its impouded for Joplin's water supply. Fish might not have to move very far to find a spot to winter over. Wonder if they stack up in the water supply lake? Or at the spillway?