Just wanted to update incase anyone else has this question. I arranged transport at 6am. We planned to meet at 5:30am and walk off with our luggage. They were already calling floors of self assist by 5:15am.
We waited outside for 15 minutes for our ride and they arrived at 6am promptly and we got to Stanstead Airport very early, no traffic. We had a 11:35am flight. We sat around, had sit down breakfast at the airport and just waited for our flight. Security line was 5 minutes according to the board.