I don’t QUITE remember where our Randy Quaid Family is supposed to be in relation to the other star players, but assuming that they’re somewhere southwest-y, since they later come across Area 51 with Will Smith, I’m thinking maybe they’re supposed to be near/outside Las Vegas? We see the big destruction setpiece from the POV of New York City, Washington DC, and LA, but I don’t think we catch up with the trailer/RV caravan again until the next day (in the movie’s timeline).
There was a scene in town with Randy Quaid a few minutes ago. Perhaps if I’d been paying attention to the set, I could have gleaned a little more info. I honestly can’t remember.