While the standard installation is ~50 GB, "repacked" versions can reduce the download size to as low as ~11.1 GB by using aggressive compression techniques.
When searching for "highly compressed" versions, it is important to distinguish between (efficiently compressed files for faster downloads) and rips (which may remove content to save space). PC System Requirements
Highly compressed games require significant CPU and RAM resources to decompress during installation, which can take anywhere from 15 minutes to several hours depending on your hardware.