I used this plan to train for Cycle Oregon, and would follow it again to train for any type of extended touring:

https://www.trainingpeaks.com/traini...p?plankey=2755

It's a twenty (or 21?) week training plan to get ready for extended touring, with climbing. It took me from occasional recreational riding to Cycle Oregon ready in 20 weeks.

The rides are specified by time, effort, and type of course. So, it might say "One hour recovery ride on a flat course, this should be a 1 on a scale of 1-10 for perceived exertion." -or- "4 hours, flat to rolling course, 1-4 effort on a scale of 1-10."

The long rides were back-to-back, building up from 1-2 hours, up to 5 hours. I usually did those on weekends. Week day rides were normally 1 hour, sometimes base building, sometimes climbing, sometimes recovery. All of this could be done on a trainer. If it were me, and I was doing this training over the winter, I'd sign up for a spinning class. I'd do my "hill/climbing/interval" style workouts in spinning class, and my distance rides at home on the trainer. Just to mix it up, and keep the training a little more fun.

My goal was to do Cycle Oregon & be trained so that I could enjoy the experience, not just survive it... and I did. I was riding with my smile on.

Good luck!
Blueskies

p.s. Are your riding with a group? Is it an organized tour? Will you be carrying your own gear or have support? I ask because we're thinking about next year's vacations, and a bike tour is high up on the list of possibilities...