I'm planning a trip to Glacier National Park in early July. Would like to ride the Going to the Sun Road but I know there are restrictions on cycling sections of the road during peak season.

Most references to cycling the GTSR during peak season (when open to cars) recommend going out as early as possible - around 6:00 AM - in order to get through before the 11:00 AM cut-off. I've not picked up on any ride reports/suggestions where people have started their ride at 4:00 PM. Since it looks like sunset is after 9:00 in early July, it seems like there's plenty of sunlight to complete the ride. Wondering if there's any practical reason why doing the GTSR late afternoon into the evening doesn't seem to be as common as early AM. Is it because of more traffic? Something else?

Thanks in advance for any tips.