Hey,
I was also trying for an whole day how to disable the responsiveness of theme, because the layouts of certain posts crashed when viewed on mobile devices
This morning I found the solution.
edit the style.css of the theme and delete everything below this entry:
@media screen and (max-width: 1152px) {
Further if you’re goog in css and if you have time you can modify the settings in each of the @media tags, there is one for any browser resoltution like you see above 1152px, 960px, 640px.
I hope I could help you, take it as a late christmas present ??
Greats
Fabian