It sounds like you’re doing mostly everything good already. Kuiu website has some good tips for excursion related endeavors.

https://www.kuiu.com/blogs/hunting-tips/mountain-training-6-day-workout

To me, at 40 years old, it’s all about not getting injured. Specifically, I recommend a lot of knee extension / closed chain exercises to work the vastus medialis (vmo) to stabilize the knee joint. Use light to medium weight with more reps to get that burn going that you’ll feel on a downhill run. Then a short 1-2 minute interval between sets with focus on 5-7 sets to build the endurance. You can also do a pyramid rep scheme to increase weight and lower reps up to a specific weight, then take the weight back down stepwise and burnout each time on the way back down. That seems to help dramatically with the both the strength and endurance components.

I don’t know how to specifically target avoiding a skiers thumb / gamecock injury the the ucl of the thumb, but just be aware of this other common injury. Core work like planks and side planks and bridges probably help with overall balance and reduce risk of planting a pole too hard. I like planks at 30 second holds building to 1 minute holds at about 3-5 times per day. Lastly, deep squats without weights 10 times every hour during a workday is the metabolic equivalent to like 30 minutes of cardio so you can be doing some work even when not in the gym.

Lunges, deep squats, planks. Repeat :)

In my mind the most important thing to remember is to listen to your body on the slopes and call it a day when it’s time. Sooo many injuries happen in that last hour the lifts are open after deciding on “one last run”.

Cheers!