Node template suggestion based on date field

I am trying to get different templates for events node based on the date of the event. The content type used will be same for both, ie. Event.

This is what I have done so far:
Created a content type: Event
Added a date range field: field_date

This is what I need to get:
If the date of the event is greater than the current date, template suggestion will be node--upcoming.html.twig
If the date of the event is less than the current date, template suggestion will be node--past.html.twig

I tried with the following code:

function strive_theme_suggestions_node_alter(array &$suggestions, array $variables) {
  $node = $variables['elements']['#node'];
  
  if ($node->getType() === 'event') {
    $date = $node->field_date->end_value ?? $node->field_date->start_value;
    $current_date = new \DateTime();
    $date = new \DateTime($date);
    $node_type_suggestion = $current_date > $date ? 'past' : 'upcoming';
    $suggestions[] = 'node__' . $node_type_suggestion;
  }
}

Doing this, I am getting node--upcoming.html.twig for all the event nodes.