peter I’ve got a lot of success with a usb over Ethernet powered hub (one that definitely supports audio- not all do that).
This is working great and while I’ve never tested it close to its described length, you could easily run 20m if needed.
Running an iPad without charge is too much of a risk, I do gigs outside (shaded) in sunlight and barely can see the iPad content (very new M2 iPad Pro), let alone I do more than one gig a day many times and need my iPad charged.
With usb c iPads you aren’t bound to buying and using Apple Original camera kit adapters only. Just about any of those with a charge port would work perfectly.
Mind you, I’ve plugged into a guitar pedal (Quad Cortex) that started acting up and completely was unusable once I plugged in the power to charge the iPad. Some devices cannot be used like that.
Audio stops usually is because something is wrong with the audio path, many times it’s simply the cable, I’ve spent a fortune on cables claiming to be usb audio cables made from some special material. Mostly waste of money. Get something similar to what comes with most sound cards and then a few backups. Stay UNDER 2m you’ll be mostly fine. Most 1.2m ones would work great. I’ve had a lighting app on the same iPad crash and cause an issue with the audio stream. Keep only apps you have to have open. I now run my lighting app on a second iPad using network over BT.
This hub works great for audio
https://a.co/d/8yBJRgA
I have a few of those adapters from different manufacturers all cheap ones all work well.
Buy a two or three you will be ok.
https://a.co/d/8ozHKCp