You're going to do a demo of a network connected device in a new place? Bring your own network. If you can bring all the parts with you, that's even better -- a self-contained system that has no external dependencies is best.
If you absolutely need network connectivity, bring a cellular-wifi hotspot that you've already tested. Talk to the site organizer to find out what cell networks work there, and if you need to, buy a SIM in advance.
If you don't have an IT organization, you are the IT organization, so be a good one.
While I emphatically agree with you, if the person doesn’t know what they are doing, following your advise can cause major havoc too.
As someone who has hosted hack days in many countries on six continents and prides himself on providing a reliable and friendly network (including hand-on supporting IoT folks) for said events, it’s really freaking annoying when someone starts blasting their AP at ridiculous power levels for their one-off use case effectively muddying to hell the RF spectrum of the event space.
Irregardless if we were prepaired for them or not, or if they listened or not, there should be an expectation that you know how to use the gear you bring if you bring your own gear.
It’s the equivalent of bringing a machine gun to a shooting range and spraying bullets all around you (missing everyone, but still causing a bad time for all involved) because you don’t even know how to hold it properly.
these solutions are useful for more than "just when corporate IT sucks".
example:
I need to debug a test-mode stripe webhook and normal approaches have failed for whatever reason. solution: fire up a dev environemnt locally, ngrok it, add the ngrok address to the staging webhook list, profit.
The chances are, your home router will still have default-deny inbound firewall even in IPv6 world.
So you will need to either configure router to open the firewall, or use a solution like this. Which pretty much like current situation -- you need to either configure router to make a NAT mapping, or use a solution like this one.