We went last year and had lunch at CCR, so we only went into DCA, but it wasn’t terribly busy. I have pictures from the balcony there without many people in them even though it was mid-afternoon, and I can tell from my photo timestamps that we weren’t waiting too long for the rides we went on (Monster’s, GOTG, Ariel, Heimlich, RIP...)
This year could be a lot busier since I think there’s a “visit before SWGE” push happening, but that’s how it was last year, anyway.
ETA: We didn’t arrive until about 10:30, and only stayed until 2:30. Did at least those rides, Animation Academy, and had lunch at CCR... so that’s not a crowded day.