a lot of dc is closed on the 4th. hotel restaurants are about the only ones open. the mall is packed with people, they arrive early. the place is a zoo. takes 2 hrs to drive back out. call the embassy row hilton hilton TEL 202.265.1600 and ask if they will have a special and the roof open for fireworks. it is plenty close enough.
plan to walk back from wherever, as i would guess there will be a million people there........maybe two million
also try the lenfant and a few others in the area with tall and particularly a rooftop pool. we did the hay adams a couple times until it got so pricy, even we quit going. price got to $1000, and we even had friends at the hotel.