Race simulation - start out easy and at the start of hour 2 you should be in high Zone 2, the last 30' are Zone 3. Go right into the run brick.
Race Day Specific - 45 min
Off the bike, start out easy - get your bearings and pick up the pace gradually. After 10' you should be at race pace - remember to hydrate and run even paced. Try to run race pace for at least 25-35 minutes.