Hi, and thanks for the kind word, glad you like it! 🙂
BoldR Lite has a max-width of 1000px and narrower alternative layouts for smaller screens (respectively 768px, 440px and 310px, automatically switching to the one that fits best).
If you know some CSS, you can certainly customize this by adding some custom code in Customizer > Additional CSS.
Otherwise, BoldR Pro would certainly suit your needs: it offers an option to set the maximum width (useful when you want your site to be very large, but not crazy large on ultra wide screens!), and automatically fits the width of any screen that is smaller than this.
You can have a look at the demo site for an example: http://demo.iceablethemes.com/boldr/ The max width on the demo site is set to 1240px (which is the default and could be changed to any value).