I carry a Moto G4 dual sim in addition to my work phone (Samsung S7) . It's 4g so takes advantage of the best networks in Europe, Asia and Australia. I was just in Russia - Moscow and Krasnoyarsk, and kept my roaming costs down with a Yota SIM bought at the airport, with a Toggle (multi-country) sim in the other slot.

The Moto works so well I'd happily use it for my workphone all the time if I had to. It's much cheaper.