There shouldn't be anything jupyterhub-specific for offline installation. Since JupyterHub is a Python package and it requires configurable-http-proxy, a nodejs package, any mechanism for offline installation of Python and nodejs packages will work. For instance, you can use `pip wheel` for the Python packages:
pip wheel jupyterhub
and npm shrinkwrap for the javascript:
npm install configurable-http-proxy
npm shrinkwrap
Then pack up the results, send them to the target machine, and unpack them.
-Min