Personally, I’d buy a diamond and put it in a ring.
It’s none of the d*mn government’s business what you do with your money.
A. I never travel with my good jewelry (my knock offs look fantastic anyway)
B. Diamonds aren’t liquid at all. The mark ups are insane and you never receive near their value in exchange. (Ask the lonely hearts selling engagement rings on eBay).
C. Best idea is the poster who suggested a lump sum in an Amex account. Fees are nothing compare to the security you’ll have knowing the money can only be accessed by you.