Connect on your phone or other device. Connect to travel router. Clone the mac address of your device. Connect router to wifi. Adjust device to not auto login. Good to go.
$ python3 -m venv env
$ env/bin/pip install vrun
$ env/bin/pip install foo # assume foo depends on bar and tries to start bar via subprocess
$ env/bin/foo # fails because bar is not on the path
$ env/bin/vrun foo # works
`foo` is now executed in a process in which the virtualenv is fully activated and will find appropriate dependencies on the path if it tries to run a subprocess, etc.