How safe is modern Linux with full disk encryption against a nation-state level actors?

Let's imagine a journalist facing a nation-state level adversary such as an oppressive government with a sophisticated tailored access program.

Further, let's imagine a modern laptop containing the journalist's sources. Modern mainstream Linux distro, using the default FDE settings.
Assume: x86_64, no rubber-hose cryptanalysis (but physical access, obviously), no cold boot attacks (seized in shut down state), 20+ character truly random password, competent OPSEC, all relevant supported consumer grade technologies in use (TPM, secure boot).

Would such a system have any meaningful hope in resisting sophisticated cryptanalysis? If not, how would it be compromised, most likely?

EDIT: Once again, this is a magical thought experiment land where rubber hoses, lead pipes, and bricks do not exist and cannot be used to rearrange teeth and bones.
I understand that beating the password out of the journalist is the most practical way of doing this, but this question is about technical capabilities of Linux, not about medieval torture methods.