Training on a trainer

I would do 4 or more days and go by time, not mileage. 

Last year one of the coaches on this site Jorge, had a winter plan.  It was listed on the mentor group and he had weekly workouts.  The plan was based on timed workouts at certain levels.  He had two versions up one for power meters and one for HRM/PRE.  It looked easy at first glance but it was a kick hour.  You may woant to check the archives and look at it.  I cannot speak for him, but am hoping he does it again this winter.  If not I did keep all my print outs from last year.

Joe

Oh and if you have not yet, buy a good fan and something to keep the sweat off the bike.

Oddly enough, I travel only 0.0 miles on my trainer every week... :p

In the winter, if I get 2-3 hour rides on the trainer, I consider it a success. I usually don't get back on t he trainer until after the holidays, though, and typically start at 30 minute rides.

I wouldn't let the season /weather dictate my training.

I have a training plan, and the weather will determine how I complete it, not the other way around.

also, IMO, the trainer can be a very usefull tool all year round.