You definitely want to be training over the winter. It sounds like your going to need to do this on a trainer or rollers. For the next couple of months your going to want to concentrate on base 1 and base 2 building workouts. I would suggest no less than 4 time 1 hour workouts per week. One way to make these go faster is by watching all the tdf stages that you still have recorded on your DVR. Visualize yourself as being part of the race.