We only live 4.5 hours away, not 7-8, but as Premium APs almost all of our DLR trips are quick weekends.
We tend to leave on Friday afternoon (skip out of work early) and hit the parks by 7-8ish on Friday night. We always ride HM first and then get cherry cokes and mickey shaped pretzels with cheese to eat during the fireworks.
We then try to hit the parks fairly early on Saturday morning. We typically go to DL for an hour or so to collect a Fastpass for Space and ride some of the FL rides before we then hop over to DCA for opening there. We get our Disney Visa character greeting photo taken, pick up a Soarin' FP and ride ToT and CS while we are there. The Muppets is another family fave, so we tend to do that too while we are in the park. Typically, if we hop between 10 and 10:30 we can do everything we want to do at DCA by 12-12:30ish and then we have lunch at Pacific Wharf before heading back to DL.
We then spend most of the rest of the day at DL and in the past we have not taken a hotel/pool break. However, now that we have an active 1 year old, our schedule will surely change.
Parade time is a great time to hit some of the more popular rides. Since the parade has not changed in several years, we don't worry about seeing it everytime that we are at the parks. And, since we typically watch the fireworks on Friday (assuming that they are not cancelled due to weather) we use the time that everyone else is watching them on Saturday to also visit some busier rides. HM and BTMRR are both especially fun later at night!
Sunday morning is probably our favorite time in the parks. Even though it is an EE day, we have found that arriving at official park opening time allows us to virtually walk on to everything in FL and elsewhere in the park for that matter. Depending on the trip, we often repeat our Saturday morning routine and hit DCA for another Visa photo and repeats of our fave rides in that park. We then tend to head out of DLR by early afternoon in order to get back home with enough time to get ready for the week ahead. However, if we can swing it, Mondays in the park (especially during the school year) are a fabulous time to just relax and take it all in at a slower pace.
The key to quick weekend trips is to make sure that your favorite rides get done and then be happy with anything else that you can accomplish while you are there. Since you are Premium AP, I am guessing you make several trips to the parks each year and you know that DLR isn't going anywhere. We relish the fact that there are things that we still haven't done yet and make it a point to try at least one new ride or show each visit.