For 2 watches to bring to such an adventure trip that may last a while, I would bring my JLC perpetual calendar. I would not want to lose track of day and date without any digital connections with the outside world.
The second watch would be the Sinn U50, a tough watch ready for any environment with the German submarine steel. A workhorse movement offers trouble free operation while being a backup for the more delicate JLC ultra thin timepiece.