I think Epcot will have the "food & wine festival" going on. So they may be pretty busy. But I don't think it will be any better or worse for Epcot on that day than any of the other parks. One of the crowd calendars has Epcot at a 6 out of 10 crowd level for that day, but you can't take the crowd calendars to be completely accurate. It also has the the others parks at a 5 and 6 for that day as well. It does have Disney Hollywood at a 4 out of 10 for that day, but like I said, the crowd calendars are not something you can totally rely on. Hope you have fun. We will be there the following week after Labor Day.