Yeah, getting all your sensitive stuff off your phone onto a secure cloud service seems like the obvious approach here right? They can still escalate what they try to coerce you to do, but they don't have physical access to your data just by taking your phone, and you can also leave the phone with them and only lose the device if needed. In my likely scenario - innocent traveler, they aren't looking for anything specific, but I still don't want them to look through my files and photos just because I happen to travel internationally - that seems like it puts it out of reach (and out of obvious view) for now.