Thanks for chiming in, Kyle. Agree, there is great opportunity in winter fishing if one adapts to the condition.
When it comes to winter high flows and cold temperatures, what was once a productive hole during the summer and low flows may change. As the flows are higher, trout will seek out other niches to lie, rest and eat. Therefore, more productive fishing may be in other areas of the river as opposed to the pool. Places unproductive in summer become a trout lie in winter. During cold temperatures, it is true that trout like the deep pools, but it is likely they do not have the feed bag on. So, it is important to fancast each river section you are in, not just fish a hole. Adapt your technique to the winter conditions and trout habitats.
Temperature actually plays the most important part in winter fishing. While trout optimally like 50-68F temperatures, December, January and February are often in the 40-30sF. This significantly slows the trout metabolism and decreases the need to eat. So, instead of eating Big Macs, they sip in midges while lying still. So, an important part of the winter fishing technique is to go sloooow. Other factors are barometric pressure, light conditions and timing of hatches.