Will your bitcoins be useful to you if you are dead? If not, then I suggest something that you always keep with you, like a necklace, or a ring on your finger, or a small card in your physical wallet.
You may be traveling, but you need to be wearing clothes or at least have a little bag with you. It's so easy to hide or stitch something to your underwear or pants or undershirt, or stuck to your passport (which I take it, you guard very well so you won't lose it.)
There are special wallets for this purpose, usually sold to travelers, you hide it under your clothes. For passports, for credit cards, for cash.
Even the bad guys do it. Osama bin Laden stitched a few dollars onto his clothes when they killed him.
Osama bin Laden had cash totaling 500 Euros and two telephone numbers sewn into his clothing when he was killed.
Some people say use marine stainless steel, plastic, tungsten... For clothes, I suggest you embroider either the passphrase or the private key itself on cloth. Then you stitch that on your clothes or jacket that can hang from your belt. It can even get wet.
Of course, if you can memorize it and not forget, that would be better. I just don't trust my brain that much yet on seldom used information. I memorize my email and passwords even if it is 32 characters long, but that's because I use it every day.
