Limiting # of selections when using visual multi select widget

I have a list of about 20 potential workshop topics and I'd like to survey attendees to select the 5 that are of most interest to them. I was thinking of using the visual multi select widget, but I can't figure out how to add a rule to limit it to just 5 selections. Is that possible? Or is there another widget that would work better?

https://widgets.jotform.com/widget/visual_multi_select

You can limit the selected using custom CSS code:

.ms-elem-selectable.ms-selected ~
.ms-elem-selectable.ms-selected ~
.ms-elem-selectable.ms-selected ~
.ms-elem-selectable.ms-selected ~
.ms-elem-selectable.ms-selected {
display: list-item !important;
visibility: hidden;
}
.ms-elem-selectable.ms-selected ~
.ms-elem-selectable.ms-selected ~
.ms-elem-selectable.ms-selected:after {
visibility: visible;
content: "";
background: #fff;
display: block;
position: absolute;
top: 0; left: 0; right: 0; bottom: 0;
opacity: .7;
}

Guide: How-to-Inject-CSS-Codes-to-Widgets

Demo form: https://form.jotform.com/193428615695975

Please give it a try and let us know how it goes.