7

It is easier this way… you don’t have to touch responsive settings.
Remove fix width from page and change percentage.
If you will have two headers then just do condition if page width and put 800
Step 3 you will find if you click on main page itself and edit … the option called mobile version. But to be honest it is hustle to create whole page just because you want to display smaller header. Unless you want to make custom design for mobile