Removing the large desktop layout in less can be achieved by commenting out a few lines in the grid.less file. Comment out these two sections in the grid.less file, and the medium grid will become the largest size for your site layout.
@media (min-width: @screen-lg-min) {
width: @container-lg;
}
@media (min-width: @screen-lg-min) {
.make-grid(lg);
}
reference: http://milos.gavrilovic.rs/how-to-disable-certain-breakpoints-in-bootstrap-3/