I'd say at least an 1 1/2 hours. Route 80 is a parking lot between Parsippany and Rockaway, it's brutal. I commute from Parsippany to North Bergen (right next to JC) and it takes me an hour. I mean it, Route 80 westbound starting from Parsippany is absolutely brutal for weekday commuting.
Not to mention the traffic problems in the JC area, but I don't want to discourage you too much