I would be more concerned if it was going to hit a region with lots of active volcanic activity, like large sections of the Pacific Rim.
It wouldn't make a bit of difference to be honest. The worst place a big asteroid can hit is the ocean. The resultant clouds from the vaporization of the water would plunge the planet into a winter that would last for years, if not a couple of decades. The only place life would survive is along the equator.
Maybe so, but a single big volcano will, and has in the past, do close to the same thing by itself re producing massive atmospheric changes, and if an asteroid crash set off two, three or four big ones around the Pac Rim while also doing the water vaporization, I doubt most people will survive it.