rock & ice, graciers

What level are these 5-6 day “events?”
If they’re recreational/for fun, I’d still say go w/ the 24 week plan.
Again, if this is your first time following a structured training plan, start broad and general. Then once you’ve followed the plan for a year or so, you’ll have a better understanding of yourself and your body.

I’d recommend you think of your training with a long term mindset (i.e. years). Especially at 59, taking a long & gradual approach will yield you more consistent results while reducing injury potential. While it takes longer to build up fitness as we age, it takes MUCH longer to recover from injury by over doing it.

cover my both needs?

Climbing and aerobic endurance are at near opposite ends of the metabolic spectrum. It is difficult to train both to be physically/muscularly strong and aerobically strong at the same time (think of the last time you saw a pro marathoner compete well in a deadlifting competition or a bodybuilder compete well in a triathlon…).

Your best bet is to focus on your priority (which the 24 week program will do well at) –

Primary training objective – strengthening my aerobic base and muscle endurance.

And then return to climbing training near the end of ski touring season in preparation for spring/summer climbing 2022 (remember…play the long game, think YEARS not months)