We were there for Thanksgiving 2018. DL on Thanksgiving day, DCA on Friday and DL on Saturday.
Prior to 2018, I hadn't been to DL in 15+ years, so I don't know what "normal" crowds are, but we had what I would assume to be normal crowds on Thursday. Lines were ok, great with FP. We could easily move around the park.
Friday at DCA felt light to me, but certain lines were always super long. Incredicoaster was always 45-60, Soarin was always an hour, RSR was 90-120 minutes most of the time. We used FP though, so no problem.
Saturday was when it felt super busy. The lines were long at DL, FP were harder to come by, and there were just a lot of people. Not surprising. We took a break mid-day, and when we came back in the evening around dinner time, the crowds were much more manageable (and I was less tired and the weather had cooled down, all of which helped me be less cranky!)
Personally, I think it's a great time to go!