Wellington is 18 hours ahead of Ottawa
Best overlap: 2:00 PM to 6:00 PM in Ottawa is 8:00 AM to 12:00 PM in Wellington.
Keep meetings inside 2:00 PM to 6:00 PM in Ottawa — that maps to 8:00 AM to 12:00 PM in Wellington. Wellington is 18 hours ahead of Ottawa, which gives you a solid 4-hour window. Book earlier in it and neither side is rushing. One thing to flag — this overlap crosses the date line, so Wellington is on the next day relative to Ottawa.