This is truly a nightmare survival scenario. On the run from aliens, which you know nothing about, facing the total breakdown of social order and support. Avoid other groups of people, travel well off the main highways, and find a secure wooded site to wait it out. Better know your edible plants and survival fishing, you might be there a long time.

The standard equipment in a BOB, if set up for long term survival should get you through. This movie really drives home how important it is to have it packed and ready to go at all times, and have a "escape the city" plan

Dean