Problem with a cosplay like that is that you would actually have to look like the person to really pull it off. It's not like they wear anything particularly recognizable aside from glasses and a receding hairline, really.
It'd have the same problem as cosplaying characters that wear relatively normal clothing: People might not notice you're even wearing a cosplay right away. Their eyes will be drawn to the elaborate and bright colored costumes everyone else is wearing and not pay as much attention to "normal" human beings.
I suggest maybe wearing a logo on your shirt to give others a hint as to who you are.
If someone asks, you can dramatically flare open your coat and be like "I am.... THE NOSTALGIA CRITIC!! ...I have a graphic tee that proves it!"
Zenkaikon ~ Otakon