I fish largemouth (primarily Texas) so I’m not as familiar with smallmouth behavior. As “deleted account” ? said, bass tend to move vertically v. horizontally during colder months. They also tend to suspend more during non feeding periods. It’s less about the actual depth and more about ability to access multiple depths. You can catch them shallow but as a general rule, I want deeper water access close by. I personally wouldn’t fish something like a big shallow flat where they have to move some distance to access deeper water. As the water continues to warm, they will often move to staging areas outside their spawning sites. In my area, bass get more active a lot earlier than many fishermen realize. As the days get longer, they anticipate the season changes. Lipless and CB’s can be great cold water lures. Something like a Frittside, a shad rap, or even a wiggle wart can be excellent, especially around rock. Rock holds heat well during sunny periods and I will often look for rocky areas near deeper water.