Once you have the packages on your disk (or a USB drive), you can install them on any machine: Installing additional packages for Cygwin - Stack Overflow
Navigate to the x86_64/release/ directory. Each package has its own sub-folder containing the compressed archives. download cygwin packages manually
How to Download Cygwin Packages Manually: A Complete Guide Downloading Cygwin packages manually is often necessary when you need to install software on a machine without an internet connection (offline installation), manage multiple systems with a local repository, or grab a specific tool without running the full installer interface. Once you have the packages on your disk
For more advanced users, the Cygwin setup tool supports command-line arguments to automate the manual download process. Description -D or --download Only download packages, do not install. -P or --packages Specify a comma-separated list of packages to download. -s or --site Specify the mirror URL. -l or --local-package-dir Set the destination for the downloaded files. For more advanced users, the Cygwin setup tool