If your threat model doesn't include physical tampering/rootkits, just wipe your devices pre-travel and set it up when you get where you're going. If it does and you can afford to mitigate that risk, arrange to have cheap new devices at your destination and travel with nothing.
First password accesses clean files, second one accesses dummy [legal!] fetish porn collection ... do border guards hold you to get a third password?
An analogue analogue might be: I have a book full of "random alphanum text", I have two (or more) one-time pads for decryption of portions of the book, I also know the page/line the actual cyphertext starts at. The rest of the text in the book is random quotations encrypted using a selection of further random one-time pads. Can forensics find that there is a "hidden" n+1 plaintext when I give them the n pads and starting points? Seems impossible??
Also, sweating you out in holding is probably more effective than you realize.
If you are in a pinch.
If not you can just sell it (there or at home) and take the loss as a rental fee.