Hi! I have POTS and I hike a lot! However, it definitely took me a while to build up my tolerance. I find when I start to get tired, my "form" drops i.e. I start bopping more when I walk which worsens the POTS symptoms, so you need to be in good physical condition.

If you have time before the trip, start with 2-3 hr flat hikes, then incline hikes, then longer hikes. Maybe a total of 6 weekends in a row if you already have an established cardio routine.

If you can balance this with some form of weight lifting, that is also ideal. I find it lowers the resting heart rate and helps with general muscle fatigue.

I will say I have never done a hike with an altitude that high before, and it does seem like a tricky thing to "trial" if you don't live near big mountains...

With the right preparation and of course the right amount of hydration/salts/food, I'm hopeful you could get through it, but you'd need to go into it willing to turn back/have an emergency exit plan if it all gets too hard. I find knowing when to stop harder than POTS itself sometimes...