You can use a preprocess function to add a theme suggestion specifically for this view.
Something like:
function rodekors_theme_suggestions_container_alter(array &$suggestions, array $variables) {
// add "if" statement here to check for some value unique to your view
$suggestions[] = 'suggested_template';
// end "if" statement
}
Then you can copy the standard container template file, rename it 'suggested-template', and just remove the outermost wrapping div.
Because that views-element-container is a container around the view, you need to access / alter the code on the container level, instead of the view level. Most likely, even if your unset theme-wrappers code worked, the div would still exist, just without its class.