What I would personally do is buy a device that can connected to wifi and hotspot at the same time. This can be a raspberry pi or a wifi router range extender.
I would set the name and MAC address to match a device that is constantly connected, a smart TV or Alexa maybe.
Then I would use this device connect to the internet.
Everything works as usual and for those who monitor the network via Router settings, nothing looks different.
Have fun pulling risky moves and maybe also learn something out of it.