I have changed my mind on this, and think that the GOP ought to appeal. It's a pretty obvious constitutional violation, moreso than Florida.
Here's the argument:
Article I, Section 4 of the Constitution provides: "The times, places and manner of holding elections for senators and representatives, shall be prescribed in each state by the legislature thereof..."
The NJSC has violated the US Constitution without a doubt. The NJSC has discretion to interpret the language of the legislature's laws relating to elections. The NJSC has no discretion to rewrite the laws.