I was actually watching while they were in line and the one that was right after the first parade rarely stopped moving and it did take about half an hour. That said, the first one, who opted to get in line before it opened might be the better bet. I was watching that one as well and right before it opened at 7:30, the line was a single line, they hadn't even taped the street to wrap the line, watched them do that just before they opened the queue. Once inside, for both streams, it was very open, no crowding at all walking through. I even commented on how relaxed and distanced everyone seemed to be. I did catch a 3rd stream right before the second parade and that line looked like a zoo - long wraps and no distancing. 9:30 or so seemed to be the worst time to be there last night.
We're all vaccinated with the exception of my grandson who is 9 and can't be. We're very aware and sensitive to being cautious, but we're pretty good at creating our own distancing within our group in line. The first one intentionally stays back, the rest of us space between us putting my grandson in the middle. The last one in line gets the tough job of keeping people off their back, but a nice sequinned backpack usually does the trick.

We pretty much got our method perfected at WDW where distancing is 0.
I'm curious if it works like it does at WDW, as long as you're in line before closing, you get to go in? If so, that's probably what we'd do if we didn't opt to go at the beginning. Either way, it's a must do for us so we'll figure it out. I plan on watching a lot of streams before our trip to get a better idea of what works best.
I appreciate your first hand experiences, thanks!