Customization to show 2 rooms or 2 columns vs 3, 4 or 5.

To show 2 rooms. Put this under Appearance / Theme Options / General / Custom CSS

@media screen and (min-width:992px) {
   .rooms-row {
       width:auto;
       max-width:760px;
       margin-left:auto !important;
       margin-right:auto !important;
   }
   .rooms-row .item {width:380px !important;}
}

To target just one specific meta box, try putting the meta box ID in front of it. You can also add in a custom anchor ID and use that too.

Example: Let's say you just wanted to target the first rooms meta box.

@media screen and (min-width:992px) {
   #themo_rooms_1 .rooms-row {
       width:auto;
       max-width:760px;
       margin-left:auto !important;
       margin-right:auto !important;
   }
   #themo_rooms_1 .rooms-row .item {width:380px !important;}
}

or a Single Room

#hidethis{
    display:none;
}
@media screen and (min-width:992px) {
   .rooms-row {
       width:auto;
       max-width:380px;
       margin-left:auto !important;
       margin-right:auto !important;
   }
   .rooms-row .item {width:380px !important;}
}

Cheers!