Yeah, forgot to mention that.
I took 14 days, and I rowed only half-energized most days. One day, just to see how far I would travel, I didn't row at all, only taking positioning strokes to stay in the current. I loafed along and did 15 or so miles that day, IIRC. So anyone who wants to exert themself can get down in far less time than I took.
A couple of other factors to consider. I had virtually no upstream wind -- you may not be so lucky. The days are short and getting shorter that time of year -- your shore routine may be impacted, depending on the size of your group. Being by myself, I had a real quick meal routine and minimum camp setup/takedown time. There were a few mornings when I had ice in the water bottle, but the weather there is still pretty good. (Yes, well, there was that October 3-4 years back, when it was raining, cold, and miserable for a week or so in mid-October, but the law of averages will be on your side.)
Hope this helps.