Hi, Ryan. I've found that the bass may use shorelines well down into the 40'sF. But at that point, icing is imminent. What I've seen is that when icing begins the bass drop away from the shorelines and begin to hug bottom more. When the surface freezes, the upper layers are coldest, and warmest water (~40F) is on the bottom due to ~40F water being water at its most dense, and bc the ground retains heat.
However, this is may not be the whole story, as the water directly beneath the ice for much of our winters is 38F! The whole water column will be 38, except at the very bottom, where it's ~2deg more. So there may be avoidance of colder upper waters, or innate concerns over stranding? Also, some areas with ice cover will become stagnant and if there is much vegetation in there its decomposing and lack of fresh water recharge can make for an anoxic toxic soup. Some of these are prime habitat for bass in summer but become toxic wastelands (except for bacteria) under ice and snow cover.
Cover/objects can remain important, so look for that. Even dead weed beds act as objects. That’s part of the draw of the bottom too. I know one spot on a fairly cover-free pond where a chain-link fence goes out into the water. It’s a bass magnet in winter.
Winter waters tend to become very clear, with the lack of planktonic algae in the water column, and bc the denser water near the bottom has suspended sediments settle out, barring heavy winds. So, clear water and the die-back of vegetation beds, I go lighter and lighter in tackle. By mid and late winter I may be using an UL rig with 4lb line. Winter bass seem to prefer small, even tiny, baits, esp by mid-winter.
Early and late winter often offers the most receptive fish, or… mid-winter the least. So I adjust expectations of a “good day”. This will vary though, of course, with that particular water body and the conditions & circumstances prevailing. So, don’t be surprised if you are pleasantly surprised here and there. Or if you take a skunking.
Nearly all my videos touch on C&C and how the fish respond. The video fishing journals (VFJ's) often have a seasonal focus, yet the seasons are progressive, so... it's tough to understand winter without understanding what the other seasons are how they come about.
Hope this helps,
Paul