Remote desktop: Fullscreen is limited to the resolution of my primary monitor. How can I get a full screen rdp session on my second (bigger) screen?

The solution is to set the resolution in the view tab manually to that of your big screen (1920x1200 in this case), instead of "fullscreen".

This is due to the fact, that the initial RDP window always opens on your primary display and will take that display's current resolution as "fullscreen".

You can set ANY resolution you like by editing the .RDP file in a text editor!