Knowing if there is a portal open

[knownasilya]

Basically I want to know if there is a portal open for a given id:

{{#with (concat 'footer-' elementId) as |portalName|}}
  {{#if (portal-open portalName)}}
    {{portal-for name=portalName}}
  {{/if}}
{{/with}}

Basically I tried to do the same with a computed property and the service, but it requires setting up dynamic CPs (since I'm using the id) which is way too much work if you have multiple portals.