I would leave early. Even at this time of the year, the NJ Turnpike just south of Exit 8A where it merges from 5 lanes to 3 can be all backed up for miles. I know this because I live in that area. At the time you're thinking about leaving though, that shouldn't be a problem.
2007 - Majesty of the Seas (Bahamas)
2009 - Enchantment of the Seas (Western Caribbean)
2010 - Freedom of the Seas (Western Caribbean)
2013 - Golden Princess (Alaska, roundtrip from Seattle)