If you are using two monitors as an extended desktop you can use VLC in fullscreen on second monitor by adding the following as command line switches to the shortcut you are using. After that you can still see the VLC control window in your first screen but the video is displayed on the sencond screen.

--video-x=1600 --video-y=400 --width=300 --height=300 --fullscreen --no-video-title-show --no-embedded-video --no-qt-fs-controller

Have fun!