Hi James,
Sounds like an awesome trip! The TRX is a really useful tool for this sort of strength training.
I suggest using the “Bow and Arrow” movement to replace the single arm row. You can weight this with a vest or adjust the length of the TRX strap to increase difficulty. Here is a link to that exercise: https://youtu.be/H7BCwIXolkg
You can do a TRX “Low Row” to replace the cable rows. Same variations with vest and strap to increase difficulty. Here is a link to that exercise: https://youtu.be/rXptjrVbhgg
And triceps extensions can be done on the TRX too. Video: https://youtu.be/xODm0GuXPMY
Start with maybe 3 sets of 8 reps of each exercise for a month and progress to higher reps as you get closer to your Matterhorn climb.
Resistance straps are useful too. Generally, you can do a higher number of reps at a bit faster pace until you feel that muscular burn. The exercises are essentially the same, with the strap wrapped around a solid object you can pull/push against. You should be able to easily find videos for those exercises with a google search.
Hope that’s helpful! Good luck on the Matterhorn and let us know if you have any more questions.
Coach Leif