I have a vuetify select where I want to restrict the text when too many elements are selected.
So I used conditional rendering to just display what I want:
<v-col cols="auto">
<v-select label="Select" :items="items" hide-details v-model="selectedItems" multiple>
<template v-slot:selection="{ index, item }">
<div v-if="allSelected">
<v-chip v-if="index == 0">All selected</v-chip>
</div>
<div v-else-if="selectedItems.length > 1">
<v-chip v-if="index == 0">{{selectedItems.length}} selected</v-chip>
</div>
<div v-else>
<v-chip v-if="index == 0">One selected</v-chip>
</div>
</template>
</v-select>
</v-col>
As you can see, there are just 3 branches (all, some, one), each displays only one v-chip. But depending on the number of items selected, the select needs more or less space.

When changing cols to a specific number, the height increases when there isn't enough space.
Playground
Here is the playground where you can see that the select changes the size depending on the number of elements.