Secondary Sidebar ALWAYS on left (responsiveness issue)

In Twenty Fourteen, when the screen size goes below 1080px wide, the secondary sidebar drops down to the bottom of the screen.

Unfortunately, I’m using Ubermenu in my secondary sidebar, and it will not display properly in the bottom location.

I appreciate the responsiveness, but the secondary sidebar is the most important navigation area on my site. I need it to be visible at all times. The top menu, content sidebar, and even main content area are less important, and I’d rather push one of them to the side (or bottom, as the case may be) than the secondary sidebar.

Is there a way for me to make sure the secondary sidebar ALWAYS displays on the left side of the page, regardless of screen size?