Having traveled with HTC and Samsung 120/60 & 220/50 dual rated chargers, I would say "it works." Though I carry a dual rated surge protector and plug adaptor with me.
Most "kit" is dual-power per the labels. Do use a surge protector! There's nothing like plugging in your new best gizmo abroad and getting a bright blue spark from the adaptor - with NO surge protection in place... I count myself lucky that I have never fried anything ... Thus far.
If you realize you can't use VZW where you're going, consider some unlocked phone, rental, purchase or loan, with a local SIM. I tried TMo on a recent trip and am still cleaning up from the total waste of money and time. Now I also have an AT&T phone, unlocked...