"Jersey Week" definitely is crowded on the Friday-Saturday-Sunday, which will be November 8th, 9th and 10th. Before that in the week, it's not too bad, but that particular week can be busier than weeks surrounding it.
I always believed the increased crowds is due more for the long weekend of Veteran's Day, which many kids have off, making it an ideal time for many families to plan a vacation with little school missed. It isn't just Jerseyans filling the parks. Also there are many events at Disney that weekend, like the Super Soap and Food and Wine.
So that particular week is busier, but not Easter or Spring Break or anything!