Update: we still have room for one person for the room at the Days Inn Baltimore Inner Harbor. With four people, each person would pay $120.50 or so total.
We also have room for one more person for a room at the Sleep Inn Inner Harbor from Sunday 8/4 into Monday 8/5. We decided it would be best to extend our stay, but there was no availability at the Days Inn. The cost for the room at the Sleep Inn is $159.84, or $39.96 per person if we get a fourth person.
ALSO, we have yet another room booked at the Best Western Plus BWI Airport North Inn & Suites (say that three times fast) for Wednesday 7/31 into Thursday 8/1. We have two spots open for that room. The total cost is $88.81, or $29.60 per person if we get a third person and $22.20 per person if we get a fourth. The hotel is very convenient to access from the airport via the light rail line, and it's convenient to get to the inner harbor from the hotel via the same route.