Politically, it would be very hard now for any Republican or the courts to overturn this. The backlash would be career-killing and legacy killing. When you're fighting an unwinnable battle, the best thing you can do is restructure so that you have a chance to win the war.
I would actually be quite concerned about it being overturned if Ginsburg died under a Republican president and senate. The fallout would be Dred Scott level, but they only need one more vote. 2016 just got a lot more important this week, with gay marriage, housing discrimination protections and a fully intact Obamacare now on the line.