Don’t worry, no big download waiting for you is waiting for you

Guerrilla Games has confirmed on Twitter that the Day 1 patch is only around 250MB:

The game releases on February 28th in North America and on March 1st in Europe. We’ll share our review soon, but it’s nice to confirm that the general consensus from the already published reviews is that Horizon Zero Dawn is a strong new IP with just some minor problems.

No details of the patch were shared, but with such a small size we expect only minor fixes to be implemented.