> If you are an important politician, an opposition figure or a dissident of some kind, some unfriendly country might decide to invest lots of money in order to gain access to your data. A six words password (77 bits of entropy) should be out of reach even to those actors for the foreseeable future.

In case you are in this position I fear that increasing password strength is one of your least worries. We saw with LastPass breach that it is possible to install a keylogger on one of security specialist's machine which ultimately defeats any password. IMO you'd better find a specialist or a company you trust to safeguard your devices' from any malicious apps.

P.S a mandatory XKCD's comic https://xkcd.com/538/