Where do the shad go in winter?

" Where do all the shad go during the winter?" Diascund, Waller Mill, LCR, Chesdin, and so on other lakes are loaded with shad during warm weather. Sometimes my screen is blacked out because there are so many. But when temperatures drop and winter starts to set in you don't see a one. Look all over and can not find hide or hair of a shad.
I have heard, that they die off, lie dormant on the bottom in deep water,they get into shallow water in back of creeks. I know they don't go to south for the winter, so anybody got any thoughts or info.

I really don't know but the one lake that I fish through the ice has shad and they will show up on the screen about 5 feet below the ice. I fish for them when I need bait for walleyes.

Another lake they move to the deep end of the lake in 30 fow. Catch one by accident once in a while but not too often. I do know that they migrate to the shallows come fall.