Contested Ground Studios (CGS) produced a game called Hot War, a scenario where the Cold War went hot. While the game is, like T2k, set in the aftermath of World War Three, Hot War is set in the 1960s and more importantly, it's a horror game and has weird science and the occult as central elements.
While this is obviously not going to be everyone's cup of tea, the game deals with factional splinter groups, paranoia, hidden agendas, investigation and subterfuge on top of the survival and rebuilding themes.
Hot War preview: -
https://www.flamesrising.com/hot-war-preview/
Again, it is a horror game but people might find elements of it useful for T2k and at the moment, it's in a bundle with a parallel game from CGS on DriveThruRPG for free. I say parallel because although Cold City also takes place during the Cold War and has a similar theme of horror, weird science, conspiracy and investigation, it isn't so much a companion game as an alternate reality version (for example, the timeline is earlier in Cold City so WW III has not happened).
https://www.drivethrurpg.com/product...-Bundle-BUNDLE