Stop thinking of the trainer as something that is only good for low intensity base miles. If you are slogging along spinning aimlessly, even watching a movie, a trainer can be mind numbing torture and probably isn't doing much for your fitness. The key is variety, make each workout have a purpose. And this is another topic but don't believe the old bromides about only spinning at a low heart rate during the winter base building period. My coach has me doing a mind boggling variety of routines that never bores. Some days are low intensity recovery, some are lower cadence hills grinds and many are pretty intense. Most workouts are about an hour, including a warm up, and the longest is 90 minutes. For example one I did recently: 290 watts for 3 minutes, 30 sec rest, 300 watts for 2.5 minutes, 30 sec rest, 310 for 2 min, 30 sec rest, 320 for 90 sec, 30 sec rest, 330 for 1 min, 30 sec rest, 340 for 30 sec. After a spin of several minutes I do it again. I finished with a set of 400 watts for 45 seconds with a 2 min rest done about 6 times. These aren't spirit breaking and in that hour there is only about 20-30 min of intensity. The varying interval and rest lengths keep your mind occupied and the time really flies. Keep track of your wattages or speeds etc., mark the dates and review periodically to see progress. So my advice is to incorporate variety and intensity so you emerge from the winter more fit.