I want to say that it shouldn't be a problem, but there are times when you never know. I did see on Miceage that they are doing an event that weekend as well, but I don't know how many people they draw to their events.
But here's some info that might help you. I've done the DL 1/2 the past 5 years and gone into the parks every time. That event is held over Labor Day weekend. It's not crazy like this time of year, but it's not slow either. I've never seen wait times over an hour except ST (but it had just re-opened). I also know that there are less people registered for the Tink 1/2 than the DL, by a couple of 1,000. Also, Tink is geared more for women whereas DL is mixed. I know the w/ the Princess race in WDW, some women come and run w/ friends as opposed to bringing their families, so less people.
There's also a 3:30 time limit on the race and that starts when the last person crosses the start line. So even if the last person crosses at 6:15, they should be finished before 10. And Disney does have sweepers to pick up people who have fallen behind, I've never seen them, but I've heard from people they do enforce they time limit.
Not sure where you're staying, but the only place you might run into trouble is on Harbor where Disney Way dead ends, by the old entrance to the parking lot. We run into DCA through there and you'll have to wait until there's space to cross to get across. But they usually have a guard out there helping you get across. But by the time both DL and DCA open Sun. morning, everything should be fine.
And if you're staying close to the start area (PP) and Katella/DL Way you might hear the dj around 4:30 and fireworks/PA System around 5:45.
Hope that helps!!
