It really takes up almost all of the Ile de la cite. I remember buying gelato right next to it about ten years ago and remember how it loomed over the area.
Can’t recall on which thread someone doubted that daily services continued at Notre Dame. A quick search shows...
SERVICES SCHEDULED DURING THE WEEK
You can attend Mass at Notre Dame during the week, from Monday to Saturday.
Every Monday morning at 8AM, a Mass takes place in the choir. If you wake up later, you can also attend 9AM Mass (except during the months of July, August, and the first 15 days of September).
Every weekday and on Saturdays at 12PM, Mass takes place at the main altar.
You can also attend Vespers at 5:45PM, from Monday to Saturday. It is followed by Mass at 6:15PM at the main altar (6:30PM on Saturdays).
SUNDAY SERVICES SCHEDULE
A series services takes place in the Cathedral on Sundays:
8:30AM: Mass
9:30AM, Lauds service (morning hymns service)
10AM: Gregorian Mass
11:30AM: International Mass
12:45PM: Mass
5:45PM: Vespers
6:30PM: Mass generally presided over by the archbishop of Paris, an important moment for any Catholics visiting Paris.
source:
https://www.pariscityvision.com/en/paris/landmarks/notre-dame-de-paris/mass-notre-dame-de-paris