Embedded videos are not filling the iframes properly

I’m trying to get my website up and running again after installing Crio Pro. One major design issue is my videos are not embedding properly, they appear very small. I’m using the simple method (paste the link, and let BoldGrid handle the rest). I have also tried manually embedding it through the text editor, to no avail. In the back-end, the video appears around 850px wide, but in the front end it’s 450px. Way too small!

Ideally I could have control over the size, or at least by default fill the whole block its embedded in, which in this case is the width of the darkened block framing the page title (“REEL”) at the top. Any ideas how to fix this?

Thanks!