How to adjust the min px width for "full layout"? Goes too early to mobile style

How to adjust the turning point between “full style layout” and “one-column mobile friendly layout” on Onetone theme?

The problem is that now the responsive layout changes too early to one-column style for me when resizing the window. For example, when viewing the page with Safari on iPad 2 (even horizontally), it shows the featurebox section in one-column style (1×6) even though it would look a lot nicer with 2-column (2×3) or even 3-column 3×2) style.

See yourself with the theme demo site: https://demo.mageewp.com/onetone/ For me now (Chrome, Win7, screen resolution 1920×1080), the layout changes when the screen width goes to 991px or lower. I’d like the turning point to be much lower, like 800 pixels. What do I need to change to get that result?

Also, 2nd question: Is it possible to add 2-column layout between 3-column and 1-column layout for the featurebox items when resizing window? Now the transformation from 3×2 layout to 1×6 is too big jump in my opinion. Having 3×2 -> 2×3 -> 1×6 smooth responsiveness with featurebox items when reducing the window size would be awesome. That would also partly fix the main problem.

Thanks!