Whole home mic/speaker coverage idea

I do not have the ability to tinker with this at the moment, but wanted to throw out the idea for others who may be able to before me.

Would it be feasible to connect a USB sound card to Rhasspy, and then use a landline phone with the speaker and mic wired into the sound card. In theory this would then allow several cordless handests to be connected, left on speaker phone, and then have all rooms covered by one instance of Rhasspy.

Maybe this has been done or said already, but I could not find anything while searching.

Can’t wait to get hands on with Rhasspy!