Ok, how are they going to know how many BTC do you have? Or any one in your family? You can get an anonymus wallet and transfer it there for the time beeing in the US. They can't get hold of that if it is in hard wallet.

In other way, if you enter the US with the hard wallet on you is not like having money. It is the same issue if I have over 10k on my German debit account and not beeing an US citizen.