Many of our journeys cross climates: Kyoto to Okinawa, Patagonia to the Atacama, the Atlas to the Sahara.
The trick is layers that pack small. One warm mid-layer, one shell, two pairs of shoes at most, and nothing you would mind washing in a sink.
If a trip needs specialist kit, we arrange to hire it where you will use it, so it never has to fit in the bag.