This time of year, with the cooler(cold!) temps, has my dog in a really different frame of mind. He is "ON" and never flat during obedience, but we are not tracking or doing daily ob sessions like we did all summer long. So when we do train, I see more enthusiasm.
I think daily short training sessions are fine, but for some dogs it is just too boring to do the same things over and over and over. I hardly ever do a full routine and seldom pattern train. When I do pattern train, I give the reward at the same spots so during a trial that anticipation because it didn't come builds and hopefully brings the drive state up during that long routine.
We do more agility and core strengthening exercises in the winter months just to keep busy when the snow is a foot deep. I'm lucky I get to go to a couple private indoor places to train in the frigid temps, but we all hate being inside!