Just bring a cheap burner smart phone with you on holiday. You can get one for a couple hundred bucks at most these days, and it'll save you all this hassle of backups and encryption etc. Well worth it for the peace of mind.
It will also have the added benefit that if you lose your phone (which is a lot more likely than you being targeted by invasive customs agents) you won't care too much.
It will also have the added benefit that if you lose your phone (which is a lot more likely than you being targeted by invasive customs agents) you won't care too much.