Let the carping begin! Anytime someone tries to pinpoint regional idioms, there are many folks who were born and raised there and have never heard the term. Where I live, that sandwich is called a submarine, shortened often to sub. But then again, I live in Kentucky, which is sometimes referred to as the Midwest and sometimes as the South, but we have a language all our own. John Green has a whole slew of regional slang terms in the latest mental_floss video.
Still, I had never heard of the term "catty corner" until I was 27.