If I own an innovative camera company, I will make a sensor with the dimensions of 18mmx48, about the ratio of Xpan and has about the same area as a 35mm full frame sensor so it can be produced relatively inexpensively. The diagonal is 51mm which is just a bit larger than the 43mm for the 35mm cameras, so any new lens design can be made to be competitive with 35mm counterparts in terms of size and cost.
So the camera, assuming it's a rangefinder, could be between the size of a Leica M and the Xpan. If liveview works well, then you don't need a rangefinder. Otherwise, license the RF design from Cosina Bessa or Fuji XPan and you are there.
Now where did I stash that $10 million spare cash?!