I have a large living / dining room area (30 feet long x 20 feet wide x 14 feet high ceiling). 

I am interested in playing music (no TV). I currently have 1 Play 5 (Gen 1) in the area. Does a decent job. It is sitting in a corner and therefore you get slightly faded sound on the other end of the room.

All my other Sonos speakers - in other areas of the house - are fairly recent. I want to upgrade the Play 5 to Sonos Five or something in order to completely untangle away from the old S1 platform and use the new S2 platform fully.

What would be a good setup for my large room to replace the Play 5: one Sonos Five or two Sonos One or 2 Sonos One and a sub?

Again do not need a TV function.

Will appreciate advice from the audiophiles here :)