The blog part: create an .onion or .i2p site. Or create a site elsewhere but always do any related tasks through Tor at the very least (including account creation and email usage).
Not so sure about the mailing list part.

If you have that threat level, I hope you are already protecting yourself against spying on your web searches. With no protections, you could easily become a target by just looking any of these things up.

Riseup’s Purpose

The Riseup Collective is an autonomous body based in Seattle with collective members world wide. Our purpose is to aid in the creation of a free society, a world with freedom from want and freedom of expression, a world without oppression or hierarchy, where power is shared equally. We do this by providing communication and computer resources to allies engaged in struggles against capitalism and other forms of oppression.

☞ https://riseup.net/en/security

or/and https://www.autistici.org

We believe that this world is far from being the best world possible. We react by providing a platform and tools for digital self-defense addressing the need of free communication for activists and other individuals.

Which services do A/I provide?
We provide a suite of communication tools:
Email
Blogs
Mailing lists and Newsletters
Web Hosting
Instant Messaging and Chat
Videoconference and Streaming
Anonymity Services

Mastodon via tor.

If you live in such a suppressed area. Tor might be your best bet. Hosting the site on a .onion address.