Hello and welcome!
You might want to narrow your location a bit - there's quite a bit of a distance between Reston and Ashburn.

That said, I've been looking for daycares for my infant to begin in early fall, and I haven't experienced anything concerning with waitlists both for home daycares and centers. We actually inquired about that, and it seems like post-Covid, enrollment is down across the area thanks to more WFH jobs.
One center I would love to recommend is called Reggio's Treehouse. There is actually a location in Ashburn as well as a new one that opened in Reston recently. We toured the Ashburn location a few years ago but wound up not moving to that area, and we just toured the Reston location a few weeks ago. I was really, really impressed with it - the people running it seem to be incredibly knowledgeable and kind, the staff seemed to be attentive and loving, and the space was clean and beautiful. The location is a bit far from where we live so we will likely go with a different option that is closer to home, but honestly I wish I could switch what they are offering with a location closer to my house. Would definitely recommend to folks in the Reston area!