OK, let's work backwards NM....
7:50 AM flight, even though it is to Canada, it is treated as a domestic flight, since all the customs/immigration will be handled when you arrive. So you need to check in, go through security and that is about it. Alas, LAX is very busy in the early mornings. Presume you have a boarding pass and seats, I would say shortly after 6 AM to play it safe.
Next thing going backwards is the Rental Car, with a large group, I would drop everyone and the baggage off at the actual terminal, and then return the car by myself, and no need to hassle with luggage. Two of you, that depends on how you travel. Al rental cars at LAX are off-property and need to take a shuttle to LAX. Let's add about 30 minutes. (5:30 AM)
So now the drive to LAX from
Disneyland, I would say just under a hour. My preferred route (2 or more people), 5 north, get in the carpool lane asap, take the special carpool exit to the 91 west, head over to the regular lanes shortly before the 605 north exit, take the 605 north to the 105 west, once again, back to the carpool lane, to the LAX area.
So you don't want to hear it, I would say 4:30 AM to play it safe...
Enjoy your visit.