I know this sounds picky, but these trips are vacations for me, not so much "training opportunities." Except for my trip to Spain, I didn't really do any special training, and that was only because it was so early in the season. I tend to just push through, grin and bear it, as I know I can get through horrible climbs based on what I do at home. I may be slow, but I can do it. The only reason I didn't do some of the "extra" climbs in Spain was the fact I was on a rental bike where I could not reach the brakes from the drops and the lowest cog was a 25, as opposed to the 27/28 I have on my carbon roadie.
This is somewhat of a digression, but over the years I have learned a lot about myself on these trips. Each one had its plusses and minuses. Spain was definitely the best, due to the small, international group, and the leaders, who are the actual owners of the company. The riding was horrifically hard (we did 2 climbs that were on a Vuelta route), but the other parts, especially the food, made up for it. The trip to the Finger Lakes was the worst, mostly due to the weather, but I also found the scenery to not be that wonderful, coming from eastern Massachusetts, and we were riding on roads with wide shoulders, but filled with debris. I had 5 flats on that trip, and 2 more when I got home, when I finally bought new tires.
A lot to think about.