In my experience, never ever make internet access essential to any presentation. Ideally, the complete presentation is self-contained and doesn't need anything beyond the presentation program to be installed in the default manner. Relying on an internet connection or an (unknown) Perl installation is just asking for trouble if you can't test it beforehand.
I always have a static backup when doing live demos, because live demos are prone to failure. Displaying screenshots that do the "walk through" through the live demo is almost as good, and is a safe-way fallback. If you can't do it with screenshots, consider doing it as a video but consider what kind of codec you use to encode the screencast video.