It varies depending on the day, but usually I have found New France to be one of the first "main" hamlets open. If it's not open at 10 o'clock sharp, which it often is, it should definitely be among the second "wave" of hamlets to open; in other words, after Banbury Cross and Heatherdowns open, Killarney, Aquitaine, and New France all typically open at the same time 15 or 30 minutes later.
I can't think of one time I've visited this summer when New France was among the "late" hamlets to open, like Oktoberfest or Festa Italia, which often don't open until 10:45 or later.
If you really want to ride InvadR as early as possible, I would recommend arriving at the turnstiles at 9:45, when Banbury Cross often opens; New France sometimes will be open as early as Banbury. Of course, it's rare that New France opens this early, so shooting to arrive in Busch's little slice of Canada between 10:15 and 10:30 will probably still put you ahead of the crowds.