I would definitely agree to the warming up on the trainer. I have always needed a long warm up, even when I started cycling, 11 years ago, and I was, well, 11 years younger. Part of this is for my breathing, as well as my muscles. I used to do a group ride every Friday morning in the summer, when I was teaching. I could generally keep up with these people, but they started off like a bat out of h*ll, and usually we left the parking area and went straight up a nice hill. By the time we were done with that and on a flat, I was a wreck. I asked several times for a slower warm up, but the 2-3 different leaders couldn't do it. Then, one year DH and I led the rides and we did start out slowly for about 3 miles. A few didn't like it, but most appreciated it. If you ever go to a bike race, you will notice the racers all bring their trainers and warm up for a long time. In the cold, this becomes even more important. Also, the thin wool neck gaiter might help when the temperatures are not that freezing.
My asthma was once called "specious." Not sure why, except that I never wheezed, my chest just felt tight and got tighter.