Well, obviously it's a guess as we don't know what the opening of Galaxy's Edge will do across property.
I would say if you can get to AK or MK for rope drop at 8, you will still have beat a lot of people there and should be able to do pretty well. 7DMT and FoP will already have large lines, though, so I wouldn't head to those.
With HS being open from for three hours of EMH before regular rope drop at 9, I would say getting there at 9 probably won't do a lot of good.