We were there 2 weeks ago. We did DL regular entry on a Monday to make the Anna and Elsa run. DH got there just after 7:00 for an 8:00 opening. He did gate 19 and was first in line. DD and I joined him about 7:30. We were going to just stay back in the line but the people behind him in line told us just to come up. Even at 7:30 we would not have been horribly far back and I think still would have fared well in the A&E run. That day was fairly low crowds, so I don't know that every day was like that.
At about 7:40 to 7:45, they pulled their family of the day- did their little announcement and then opened the turnstyles. That started the 1st leg of the A&E run.

At that point, you will see everyone bolting to the castle where the ropes are set up. You will see a couple of people actually at the ropes to the lands other than Fantasyland and A&E, but the bulk of the crowd will be headed to A&E. Our day they did not have a dedicated line from rope drop to A&E- it was drop the rope and the 2nd leg of the run started. DH ran with the Dads and he could have been first, but knew that DD and I weren't running so he let about 4 Dad past him. DD and I did a fast walk and would not have been that far behind him in line.
If Anna and Elsa are your rope drop intention- then I would have someone in line at 7:00 a.m. ready to make the run. If you are staying in walking distance the rest of you can come a little later, and if you do not get next to each other by rope drop then just hightail it to the line to meet your runner. Your runner can always let people go ahead in the line until you join up. We let a lot of people ahead of us because we waited for Elsa to show up as we didn't want to do the line again.
If you are not headed for Anna and Elsa, then know that the turnstiles and rope drop are going to be a little more crowded than usual because there will be a bunch of people who might not normally be rope drop people there to make the A&E run. The bright side is that while if you are later, you may be behind the crowd at the turnstyles or rope drop, that if you aren't headed to Anna and Elsa- then you will be leaving the crowd and it shouldn't be bad where you are going yet!