Hello Marko,
Templates are required for specific pages to work, and loaded via buitin WP templating system. Widgets for differenty, but I’ll surprise you – there is already a way to modify EM widgets output. How to do that?
Just use the pluggable punctions. Most of the widgets output is controlled via em_display_events() function located in includes/functions-template.php. If you copy that to functions.php of your theme you’ll be able to ovverride the default widget display.
Try that and share your thoughts.