Here is a side by side comparison of the upcoming Canon EOS R5 (Adorama, B&HPhoto), Canon EOS R (Amazon, Adorama) and Canon EOS RP (Amazon, Adorama)
From the image, you can see Canon EOS R5 inherits the overall design from the EOS R, but with the upper LCD mounted and the multifunction bar changed to a joystick. The size is about the same as Canon EOS R and a little larger than Canon RP. The operation feeling is better than Canon EOS R.
The design of Canon EOS R5 has the impression that the viewfinder shape is gentler than that of the EOS R, and is closer to that of a single-lens reflex camera EOS.
Canon EOS R5 is expected to start shipping in July 2020. It is already listed at Adorama, B&HPhoto.