I couldn’t see any threads on this topic but I have been travelling in Central Asia (Georgia, Azerbaijan, Turkmenistan, Uzbekistan, Krygyszstan, Kazakhstan, Russia and Mongolia) and Monzo has worked well in all countries over over the counter and with atm. The only problems I had were in Bulgaria and one petrol station in Kazakhstan where the card was declined even though there were funds there. Other than that all good!
Sounds like a cool trip. Glad to hear Monzo was widely accepted