Hi Ben, thank you for the immensely helpful information on transportation in Paris.
When leaving France, we need to be at Orly airport by 4:30am on a Monday. According to google maps, I would need to take the N15 and the N22. Do we need tickets for each Noctilien bus? Would you recommend the T+ tickets?
Seeking Night Travel Advice
You'll need 3 tickets in total since you'll be crossing 3 zones (into zone 4). A single ticket is good for a single zone traversal. If I'm guessing your connection correctly you're taking N15 within Zone 1/2 and N22 from zone 2/3/4 so use one ticket for N15 and two tickets for N22 (you'll literally validate two Paris Ticket t+ Metro/Bus tickets inside the N22 bus ticket reader, one after another). You won't need Noctilien specific tickets for N15 / N22. You would use regular Ticket t+. It's recommended to buy those ahead of time. The buses sell tickets onboard for slightly more cost.
I hope this answers your question. And thanks for the kind words about the site.