Hey pfb! It's me Billy over in SSF!
Being able to deal with altitude varies SO much. The absolute key is that you won' t be up there very long. If something happens and you are, you could be in serious trouble real fast and you WILL need help. Being above about 1400ft is enough to get even experienced climbers in trouble if they don't go through all the motions of their acclimation routine.
For the umpteenth time, CV carbs do not some how magically re-jet themselves for high altitude. The only thing they do in high altitude is the exact same thing they do at sea level and that is keeping the carb from getting more throttle than it really needs. That's it. Nothing else. It is really nothing that a well trained wrist couldn't do with a slide carb!
I would leave the needles alone. Too hard to get to and it involves re-syncing the carbs. IF I messed with it, I would screw the mixture screws in as I went up and change the mains. 125's work good above about 8000ft. I am guessing that 14000ft could use about 115's. They're are jetting charts that could check my own guessing if your interested.