So, I'd recommend going to DCA that day (though if you have hoppers, you could try both). You can actually get a lot packed into a few hours there. I frequently go on 6-8 hour trips with my family and have seen a lot in that time. The hours do kind of stink, but they're prepping for the new night shows and stuff, so it makes sense. The good news is that it's the off-season (or as off-season as it gets anymore) so there will probably not be huge crowds. It's part of the balancing act. Short hours, fewer crowds, or long hours, insane crowds. It's a decent trade-off.