Rocky areas, stumps, depressions out of the current. They may even delay laying their eggs until deeper water warms with more structure if it gets too crowded everywhere else. One thing about nature, it can adapt in some circumstances.
I would work docks heavily, bridge pilings and any little point or break that blocks the flow and can support the eggs.... They will spawn but it wont be as easy to spot the structure as more of it will be underwater than the usual treelines, bushes and timber falls....
Really take note of regulars you notice on the water. Many of them have sunk structure during the winter anticipating this situation so they will be fishing the beds they have created.