ssh single port foward on multiple machines, possible?

I have to showcase a grafana dashboard to a group of familiar strangers. There is no VPN. Screencast is not interactive enough.

My idea is to set up a single linux user ‘demo-user’ and share the password for this user with the group. From there, everyone can create a port forward from their machine, to port 3000 on my machine.

The result would be +-50 machines running ssh -L to view the dashboard on their localhost:3000.

Apart from bandwidth issues, would this be possible? Are there better alternatives?