[css] Bootstrap fullscreen layout with 100% height

Here's an answer using the latest Bootstrap 4.0.0. This layout is easier using the flexbox and sizing utility classes that are all provided in Bootstrap 4. This layout is possible with very little extra CSS.

#mmenu_screen > .row {
    min-height: 100vh;
}

.flex-fill {
    flex:1 1 auto;
}

<div id="mmenu_screen" class="container-fluid main_container d-flex">
    <div class="row flex-fill">
        <div class="col-sm-6 h-100">
            <div class="row h-50">
                <div class="col-sm-12" id="mmenu_screen--book">
                    <!-- Button for booking -->
                    Booking
                </div>
            </div>
            <div class="row h-50">
                <div class="col-sm-12" id="mmenu_screen--information">
                    <!-- Button for information -->
                    Info
                </div>
            </div>
        </div>
        <div class="col-sm-6 mmenu_screen--direktaction flex-fill">
            <!-- Button for direktaction -->
            Action
        </div>
    </div>
</div>

Demo

The flex-fill and vh-100 classes are included in Bootstrap 4.1 (and later)