GSP don't like being moved around, they can close up for several days, I've seen them slam shut for a week. Corals can go for a day or so without lights and have no problems.
I have a 75g tank that I'm taking down and thought that I had removed all the corals, it had been sitting in the dark with no lights for maybe 2 weeks and I noticed I missed a green hydnophora (horn) coral, it had been in the dark for 2 weeks! now it's fine. Not saying you should go do this, but corals are much hardier than we give them credit for.