In that past 20 years, I took one winter off. I never did that again. I was't back in top shape until summer was over. So just don't. That's what a set of resistance rollers is for. Ride them a few times a week if you can't get out on the road for whatever reason. If I can't get out for a while during winter, I do one interval session/week and the rest mostly zone 2. I also go to the gym and lift weights.