Well, I sure as shit ain't going to be able to drive anywhere (ever see traffic on the long weekend? Imagine what it's like when every human on the planet is trying to get somewhere), and phone and internet services are probably going to be down because nobody on earth is going to be doing their jobs, as will other public services like water treatment and distribution. So, I'd do the reasonable thing, grab a gun, go for a walk to the grocery and liquor store for some supplies and go on a nice long walk to the mountains to go hang out by a glacier lake while getting obliterated on booze.
If anyone nearby has hard drugs along the way, I'd probably be taking those, too. No need to be careful with your body if you only have days left to live.