Actually, your strategy does depend on obscurity. If the CBP agents KNOW that your data is in the cloud, encrypted with a password that only you know, they can demand that you tell them where it is, and give them the password.
It’s insidious. And pure evil.
So remember to implement deniable encryption for the cloud as well, a second encrypted cloud backup, containing believable information, so you’ll have something to give them if they ask.