Total Count of Posts NOT in Selected Categories?

Do your posts have multiple categories? If not – I think individual category counts are cached, so can sum up counts:

$categories = get_categories( array( 'exclude' => $folio_cat_ids ) );

$count = 0;
foreach ( $categories as $category)
    $count += $category->category_count;

Can also just get and count the posts, that is more flexible and takes care of overlap, but also more resource-intensive:

$posts = get_posts( array(
    'category__not_in' => $folio_cat_ids,
    'numberposts' => '-1'
) );

$count = count( $posts );