Not entirely sure about the phone. How would you be hiding the wallet on it? And what are you going to say under a targeted search when they ask you why you have an airgapped phone with no SIM card in it?
It's probably easier to hide it on phone than on laptop.
If you are using GrapheneOS you can have multiple users with encrypted drives, and you can even use some random eSIM or old sim card in other account.
It's easy to disable/enable accounts and add separate PIN for each account.
Alternatively, it is easy to hide in a hidden volume on your laptop, which you could decrypt to show copies of sensitive documents such as your passport or travel insurance. Impossible to prove the hidden volume even exists.
Why would this be any different with smartphone, you can probably do exact same thing with them.
Since we seem to go to extreme measures: crack the screen, drain the battery, and nobody will ask you if there's any Bitcoins on it. Buy a replacement screen on your vacation address, and replace it on your own
Please try this experiment for yourself and tell me how long it took for you to replace the screen, but they can always just plug in external screen if they want.
How many Bitcoins do you need on vacation anyway?
If wife (or someone else) is coming with me than I guess we need much more Bitcoin on vacation.
Not really. A knife, axe or a phone allows for plausible denniability. "I was carring the knife to cut some bread, the axe to chop some trees, and the phone to make some calls".
However, when you are found with a HW, what are you going to say? Exactly.
Exactly what?
What you saying it's ridiculous, and if I have hardware wallet that doesn't mean it 100% have any Bitcoin there.
Good luck explaining to authorities that you use knife for bread, and not to kill someone, and btw if you don't carry bread with knife or wood with axe than you are a liar.