D.C.
Looks like you have games/DVDs/toys pretty well covered. Don't forget lots of food. If your child has special nightime music to go to sleep, don't forget to take it. We put the music on our phones so we have it everywhere, including the plane for resting, as well as in the hotel room at night.
When we travel, we mostly stay out of the hotel until bedtime. And it's not too hard. By the time you have dinner out, go for a walk, dawdle a little on the way back to the room, it's time for bedtime snack in front of the TV, then bed. If your hotel has a DVD player in the room, even better because you can show those DVDs that you brought for the plane.
I actually find morning in the hotel to be more challenging. I know the people in the rooms next door probably don't want to be awakened at 6:30AM every day by my kids playing. And sometimes breakfast isn't served until 8ish. So, although it's a bit tiring for me, I just get up and get the kids OUT of the room right away and go for walks every morning, until it's reasonable to expect that the rest of the world is awake.