I winter they like a little deeper, little slower water. Sure plenty stack up in the lower fly zone, which is just below the hatchery. Plenty of anglers will also flock there. However, some will hang in similar spots in other areas of the river which are less fished. Lower Fly is a good spot to get warmed up and then you can go elsewhere to aoid crowds.
I'll mention one name - Trestle Pool. However, just like with wild trout streams the people who search out the hidden gems aren't going to talk much. However, all those spots are on the map.
Here are some strategies. 1. Go to Lower Fly Zone and deal with the crowds. However, pay close attention to the type of water the regulars are fishing (note depth and current speed) and where most of the fish seem to be hooked. Also, ask what has been working. I've been having better luck with normal sort off stonefly nymphs this winter. One buddy has been doing well with Prince nymphs. Then, head downstream and look for similar spots where nobody is fishing and give it a shot.
2. Look for paths in the snow and follow to a hole. Locals can't hide where they go with snow on the ground.
When the fish are moving and the water is warmer pockets in the riffles are where you want to be. In winter they will tend more towards deeper and slower wintering pools - most, but not all, are above the Pineville Bridge.