How is one to pray on this long day of travel, knowing that the arrival time at the final destination (Canada) will be after Maghrib prayer according to Canada's time?

The Sunnah (definition) for a traveler is to shorten the four-rak'ah prayers to two rak'ahs and to combine Dhuhr and 'Asr. If you are traveling before Dhuhr enters in your country, it is best to pray Dhuhr and 'Asr combined upon your arrival at the Moroccan airport. As for Maghrib and 'Isha, you should pray them in Canada each prayer at its designated time, complete, without combining or shortening, as long as you intend to reside there for more than four days.