Call of Duty: Black Ops Cold War takes up to 250GB of drive space on PC at launch, Activision has confirmed.
That's if you want the full game installed, running at the Ultra RTX specification. This means running the game at a high fps in 4K resolution with ray tracing.
Run the game at any specification lower than that, and you're looking at 175GB of drive space.
However, you can have just the multiplayer only installed. If you do this, you'll need 50GB of space. Then you won't have immediate access to campaign or zombies.
2019's Call of Duty: Modern Warfare only recently added mode-specific uninstall options on PC - although you must have free-to-download battle royale Warzone installed. Doing this, I managed to get Modern Warfare down from 231GB to 168GB.
250GB for Black Ops Cold War is a huge install footprint, and it follows long-running criticism about the size of Call of Duty: Modern Warfare. Activision has yet to say how big Black Ops Cold War will be on consoles.
And of course, it's worth noting that Black Ops Cold War's install requirements may grow over time as updates are released. That's certainly how it went with Modern Warfare.