Ederson Peka

With this plugin, you can create as much “sidebars” (widget areas) as you need, and assign them in a per-page basis. (It’s only useful if your theme supports “sidebars”.)
WARNING: Updating from versions prior to 0.2.5 requires new set up.

Unlimited Page Sidebars

This plugin does exactly what it needs to and always works. It's great.

Does exactly what it needs to!

Assign one specific widget area (sidebar) to each page.

Trevor Anderson

Split sidebars and widget areas into responsive columns.
Two simple widgets are provided, “Layout: New Column” and “Layout: New Column on New Row”.
Simply place these in your widget area where you’d like to create a new column (split) or new row of columns.
Gutter size and responsive collapse options are available in the Customizer -> Widget Columns panel.

Tuxedo Responsive Widget Columns

Just tested this plugin, and it works exactly as I hoped for. I can now have complex layouts in any widget areas. 
Of course it's best used for horizontal widget areas like footers, etc...



Works perfectly!

Split sidebars and widget areas into responsive columns.

Unlimited Page Sidebars vs Tuxedo Responsive Widget Columns