Yes you can, just be sure to setup Data on roaming on off (or ask) and have data services on. Because if you turn them off, you won't be able to connect to BIS via WiFi.
Go into Manage Connections and choose Mobile Network Options. Set Data Services to "Off While Roaming" (that's literally the name of the setting). Set it and forget it. It prevents the phone from ever accessing data unless it's on the home carrier or on Wi-Fi.
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