When I remotely connect to my iMac at home, I’ve been switching the display down to the resolution of the (old) iPad: 1024 by 768 pixels. That way, I don’t have to shrink the image or scroll around.
The resolution of the retina display on the new iPad (2048 by 1536) is more than the native resolution of my iMac (1680 by 1080), though. So, the iPad can display every pixel from my iMac in its native resolution and have some left over for the controls of the app I use to connect to the iMac.
If I were to upgrade to a current 27-inch iMac (2560 by 1440), however, the iPad would be a little short again.