You can always connect the laptop to a smartphone hotspot for the duration of the demo, hopefully one of your members will have a suitable data package. Providing you have mobile phone 4G coverage at your club location the Zoom call will work fine. Alternatively if the club can afford it look at a MIFi box and sim specifically for this purpose.
I did think of the mobile aspect, hopefully someone on the committee has a contract. I’m on PAYG as I’m sure quite a few are. I’ll look into the mobile router idea though, thanks. 
As a demonstrator, the problem of remote demonstrations is not just what facilities are available at the club venue, the demonstrator also need appropriate facilities i.e. cameras to capture the demonstration, which probably means three of them - one showing the demonstrator, one close up on the front of the workpiece and one on the end of the workpiece. It would also be more 'professional' if there was a camera person, to move/focus the camera on the task being undertaken. This will all require good lighting. Add a good microphone and speakers for communication and it is not a trivial setup. The demonstrator will also need a screen to 'view' his audience.
For myself, I cannot get interneter access in my workshop. No landline and as I am in a steel fabricated workshop, mobiles do NOT get a signal.
Remote demos are a nice idea but they are a lot more complex to setup than many seem to think.
