That could have been a serious issue if later in the year, with very few people on the trail. I'm glad you gout out alright. As for your issues with lack of fish on previous trips. Yes, In my opinion your biggest problem has been temperature. Indirectly air temp and directly water temp. If you don't have mid fifties in the water things slow down. At around 50 it is still okay but definitely below that, you are looking at very sluggish fish and dredging nymphs on the bottom with very few takes is the norm. On tailwaters you can catch fish somewhat easier in cold weather but it is still slower than during warmer months. So in short, yes temps is your biggest problem.