Mathilde’s is excellently located. So SO close to all the restaurants, Notre Dame Cathedral, and the metro. The space fit our party of 11 (plus two babies) very well! Lots of bathrooms and showers for everyone. Mathilde is also prompt in communicating. When I had a question, I received a response within a few hours.
There are portable a/c units. During our stay, one was broken, but the summer nights are not hot and we were out during the day. They also place fans in every room.
Even though you can’t use the washing machines, there are laundromats within walking distance. Note: Paris opens late-you can do your laundry in the morning (8-9am) and not miss a thing! 😉
Overall - we had an excellent stay!