I have been told privately to leave the forum if I am not willing to run wires. So... my thanks to those that helped.
Wireless is difficult, so make sure you can return what you buy.
My take on this is that installing surrounds will be a huge downgrade in the set up, no matter how you connect it.
The reason is that you will be far too close to the surrounds and it will be a mess.
I think we have far too many systems here that would be far better 3.1 or 2.1. Actually I think very few rooms are suitable for more main speakers than 3.
As I visit friends I see pretty close to zero rooms compatible with a system beyond 3.1. I think this has a lot to do with declining AV sales apart from soundbars.
I am coming more and more to the conclusion that surround, and especially Atmos requires a dedicated space.
If I tried to put multichannel in our great room, my wife would file for divorce and rightly so. But the bigger point is that it would be a downgrade from the excellent 3.1 in the room, which my wife really likes.