If your container row has 2 equal width columns and you want to make one side stretch half of the page, you can use the Bust Out option for the side you want to stretch.
In the Gutenberg Editor:
Bust Out option is only available for 2 columns with equal widths and wide or center aligned container rows.
Also it is suggested to use bust outs only with full width pages to avoid bust out container rows breaking the layout with pages having one or more sidebars .