The outer wrapper of this video, .video-container, has its width limited to 1000px. If you want to a smaller or larger display, that is where you change it.
The video has been made to start playing from the first default breakpoint, in order not to use up the bandwidth on small devices. If you want it to play on all devices, you need to remove the container .overlay from the elements tree.
There is also a text overlay, which, if it is not needed, can be removed by deleting the container .text-overlay from the elements tree.