If... then ... Layout chooser

Current situation: I display a type of event list through an embedded website. However, there are days when no events take place. On these days, the page is empty and (apart from the otherwise fabulous layout) nothing is shown. Desired solution: An "IF/THEN" type of app that checks a website for specific (to be specified) content. In my case, if events are available, Yodeck should display the "show events" layout. However, if the event list is empty or contains the string "nothing to show," Yodeck should display a different layout (for example, an image reel or the latest social media posts). Ideally, the plugin should check the crucial website for changes every X minutes. I hope my request is understandable.