Hi,

Changing the breaking point isn't really a good option, because there is a lot of CSS which would need to be changed, also the mobile menu depends on javascript functions as well, which aren't easily rewritten as CSS.
A better solution is to add additional breaking point for the screen sizes, where logo overlaps - so from 992px up to as much as needed and adjust the menu spacings, and font size of the menu items. 
Can you share the url to your site? I can help you with css, if you want, I just need to see it in browser.

Kind regards,
Andrej

Hi Clément,

I love the desing of your site, buttons, ... 

I checked your site and I think this would work best:

@media (min-width: 992px) and (max-width: 1169px) {
    .header-classic.site-header .site-branding {
        position: relative!important;
        width:100%;
        text-align: center;
    }
    .header-classic .site-branding a {
        left: calc(50% - 90px);
    }
   .header-classic.site-header .nav-menu {
        margin-top: -20px;
        margin-right: calc((100vw - 960px) / 2);
    }
}

It doesn't reduce spacings, but it shows centered menu, with the logo on top.

Cheers!
Andrej