I have an old LG HD-TV and I have been struggling trying to make it work fine with my ASUS laptop. The problem is that when I start "twin view" using the HDMI output of the laptop I get overscan in the TV, this means that I can't see my full desktop because 200 pixels in X axis and Y axis are lost. I have read in a lot of forums that modifing the device ID using a binary file or modifying directly the xorg.conf are the only workarounds to solve this problem but after spending almost an hour I discovered that nvidia-settings have its own tool to fix overscan.
I'm using 260.19.06 version installed using the official ubuntu repositories. To change the overscan simply launch nvidia-settings and go to Xserver Display Configuration. Detect your tv and enable it in twin view or as main screen. Now in the nvidia-settings main menu select your GPU tab and search your TV, in my case it says DFP-1 (LG Electronics 32LCD2D-MD). Select it and if you don't see a scroll-bar with title "Oversan Compensation" then click "ResetDefaults" button. After that operation you should see the "Oversan Compensation" scrollbar and you can scale the output to fit your TV size.
This driver have a lot of glitches and bugs, for example when I change any configuration I can't see the "accept configuration dialog" so I need to guees where is the accept button. In a similar way every time I change any configuration I lost my system theme and get reverted to gnome default theme. Those problems didn't presented when I was using the official drivers downloaded directly from Nvidia but after the last kernel update I just can't figure out how to make them work again. :(