Along with Dana's post, steelhead won't always be in walking-speed water when it gets cold. Many times the move into slow-moving, deep water with structure when the temps drop. I've noticed this on a number of rivers throughout the PNW. The fish will be in the walking-speed water, and some times faster water, once the hydrographs come back up and the water warms.
I think being able to read water is the single most important aspect to being successful at steelhead fishing. A guy with sub-par gear and not the greatest casting that thinks like a fish is going to catch a lot more fish that the guy with the latest, greatest gear and casting skills of the revered that doesn't understand where to fish (unlikely scenario, but I'm just using it as an example). If you don't have a lot of confidence in the water you are fishing, hire a good guide. See what kind of water they put you in, and put it in context of the conditions, i.e. they might put you in faster shaded water in the summer but slower sunnier water in the winter. It might just give your confidence a jump start and get you into more fish. Another option is to go some place that has a big run of fish. You may find that you are already fishing the right water but that nobody is home.
Good luck you'll get it figured out.