Have fun! I hope you get a room in the same building as the concierge lounge.
They have board games you can play, and you can check out up to 2 movies at a time for 24 hours (for free).
Be sure to snag waters whenever you're up there. If you're pressed for time, don't bother going up there just for coffee, since DLH has coffee urns with the whole coffee set up in their buildings (since coffee makers aren't standard in all rooms); you can just snag a coffee on your way out the door.
Although I think the fireworks deserve to be seen "in person" at least once, watching them from the lounge is a lovely way to see something you've seen before.
Just really be sure to check out what they have; with a nice long stay, you will have ample opportunity to spend some time in there. We had a concierge CM that was beyond wonderful; her name was Natalie and she just went above and beyond in making us feel welcome. I'm normally not one to want to be remembered in situations like that, but she remembered and did her thing in a way that didn't make me feel like she was intruding.