I did it! Despite still having a terrible head cold, I got up and ran 6.22 miles, on my own (and the last 20 minutes I had no music because my playlist was only an hour)
I finished in 1:20:29 (did about 30 seconds of walking when I turned around), so an average of slightly under 13:00/mile.
I need to work on my recovery. While it was hard, I wasn't dying, but I just felt like a slug all day long.
The official training for my 6.66 run in late October doesn't start until August 19th, but I think I will just play around the next 4 weeks - keep doing long runs on Sundays, but not necessarily 6 miles. Do some more running around my house which has slight elevations, try some strides, some intervals, and work on my strength and agility for the Diva Dash on September 7th.