Tank up the car, fill/refresh the water gallons, etc. Brace for any civic chaos (swarming crowds doing dumb stuff) and opportunistic malice (both the petty criminal sort and the more "coordinated" disruptions, should it come to that). Stay clear of the hordes. Good grief, the electronic highway signs in NY are telling people to take mass transit to see the eclipse, yeah, let's get huge numbers of people trapped in trains and buses! And as if the Buffalo or Rochester Amtrak & Greyhound stations are optimal places to witness potential disaster. 


Re the Catholic part, get confessed tomorrow, bookmark the Litany of Loreto (or other preferred and fitting Marian devotion) for Monday, and in 48 hours it'll be done with in whatever manner it's done with.
Done all that, even the confession part (I always go on the first Saturday of the month anyway). Didn't think of the Litany of Loreto.
This is all probably nothing, but it never hurts to put one's household on a "state of heightened alert" once in awhile, just as a drill. Right now I'm freezing some of my stored water bottles, to have a lot of ice to keep the freezer cool (I have two) if power would be interrupted. Grilled chicken and pork chops on the patio would be a great way to celebrate the world finally being put right.
And one other thing I thought of, if the 3DOD ever
does occur, whenever that happens, you could always spray-paint over your windows to keep the light out. In an apocalypse, having messy windows would be the last of one's worries.
(And not to TMI, but we just happen to have not one, but
two, portable toilets, from when my mother was sick and disabled. So there's one more problem solved. For those who would dismiss such considerations, try "holding it" for 72 hours, and let us all know how that goes. No pun intended.)