OP mentioned having ADP and automatic backups enabled and I believe iCloud sync uploads photos continuously. The biggest risk is as you say battery saving and if it will upload data over mobile data (should be a setting for that).

Further than that I would say the big question is if someone else would actually be able to access the data if OP is detained… and of course https://xkcd.com/538/ (I don’t think the random chuds in ICE would have the know how for any technical bypass)

Eventually but I give it at least 1-2 years more. Too much big money has been put into this and they won’t just let their investment die without a fight