Our group of 10 traveled in to DC for a long weekend. Colin was extremely responsive to any questions we had and was gracious enough to let us check-in well before the actual check-in time.
One thing to be aware of is the main house only has one shower, so you may need to plan out a shower schedule with that many people in one place.
The neighborhood felt very safe and was nice and quiet at night. It's only a short walk to the metro station with plenty of food and shopping options nearby. We highly recommend staying here!