We will change 2 column grid into 3 and disable sidebar.

1. Firstly please set 2 columns

2. Please add this CSS below to your additional CSS ( You can read more how to add it here). It will transform 2 columns into 3 on the desktop and hide the sidebar.

@media (min-width:1024px) {
.archive:not(.post-type-archive-estate) .mh-grid__1of2,
.blog .mh-grid__1of2 {
width:33.3%!important;
}
}

.archive:not(.post-type-archive-estate) .mh-layout__sidebar-right,
.blog .mh-layout__sidebar-right { 
display:none!important;
}

.archive:not(.post-type-archive-estate) .mh-layout__content-left,
.blog .mh-layout__content-left {
width:100%!important;
}

3. You can visit your setting and change default max number of posts per page "10" to e.g. 12 so the pagination will always look good (when there are 2 columns on tablet or 3 columns on pc).

12 elements: