Switch style plugin of a view based on results
I have finally discovered a workaround, that may be the solution for some. I display the view using Panels. Using visibility rule, there is possibility to limit visibility of view based on number of results of that view. The steps could be:


Create a Contextual filter for your view for field Content:Nid. This should correspond to argument of your Ctools Page (so that path of a page is similar to something/%nid). You may need to add Relationship, if you want to display content, that is related to the content with nid.
Create a Context display for your view.
Create a 2 separate displays (Content panes) for your view - for one result and multiple results.
Create a new Relationship based on your view for your Panel (at the Contexts tab).  
Add both your content panes to the panel.
Add Visibility rules to both panes. You should choose PHP-based filtering and enter something like:


if (count($contexts['relationship_view_from_argument:name-of-your-view-ctools_context_1_1']-&gt;output['rows'])==1) {
return TRUE;
}