Definitely, please do.
All Glacier calling and messaging is done using the internet. As long as you are connected to the internet without any restrictions, using wi-fi or your device’s signal, then everything will work just as it did when you were at home. If you plan to reconnect or reinstall the Glacier apps after arriving at your destination, you simply need internet connectivity.
Please be sure to contact your mobile provider before you head abroad to make sure you can send and receive data with your phone wherever you will be, especially if you plan on reinstalling Glacier or wiping your phone while away from home.