via Camerasize.
The Sony A6500 has almost the exact same dimensions as the A6300. One notable difference is the larger grip of the new camera (4,5mm deeper). And here is the difference shown by Photosku:
Preorders (Start on October 10 at 11am NYC time):
A6500 at BHphoto, Amazon, Adorama.
RX100m5 at BHphoto, Amazon, Adorama.