I'm flying to NYC, Business Class next month with my wife.
I know that Manchester Airport doesn't have a Maple Lounge, but do you get access to another lounge?
I tried calling them, but they didn't know! Maybe I just got the new guy.
As per your comments, your flight is actually with United Airlines, not Air Canada.
United Airlines do have not a United Club at Manchester, but they do provide access to a "contract lounge" for customers travelling in Business Class, which is the Escape Lounge.
I've used this lounge previously, and whilst it's nothing overly special, it's certainly better than sitting in the terminal itself waiting for your flight.