Ever since the solution mentioned here, WP has been updated and now allows you to manipulate the save process of wp_insert_post. If you look at the lines 3035 to 3057 (WP 4.7) the result of the check for empty title and content is stored in $maybe_empty. This variable is then run through a filter called wp_insert_post_empty_content. If that filter returns something that evaluates to ‘true’ the save process is halted. So you could have it return false to overrule the check for emptiness:
add_filter ('wp_insert_post_empty_content', function() { return false; });
Update. Note that post information is passed to the filter as well, so you can write a more sophisticated filter, for instance checking for the post type before deciding to return true or false, or impose a maximum length on the title, and so on.