Would TrueCrypt [0] be still fine for that task? (Its security audit did not reveal anything serious [1].) Is there a reason to use VeraCrypt (and trust some additional people)?

Is there anything more reliable than those two? I am especially interested in GNU/Linux.

[0] https://en.wikipedia.org/wiki/TrueCrypt

[1] Except privilege escalations, not relevant for QubesOS users.