I don't think that French people eat that much for breakfast. My farmer neighbours who work hard physically, 'traditionally' have just a coffee and a bit of bread early, they have souper (soup) at about 10 and a proper lunch at midday.
Others just eat bread or croissant dipped in coffee or chocolate but again a full meal at noon. I suppose hotels cater for that. I've had yoghurts and occasionally some of them that cater for the Dutch and may include cold meats and cheese. They charge a fortune for it though. Many people just buy a croissant in a boulangerie and have it with a coffee in local bar.
I can get away with French breakfasts on walking holidays. In gites I've also had a wider variety of breakfasts. I've had the croissant variety but also things like crepes , cheeses and even freshly cooked piperade (scrambled eggs with peppers and ham).
When I'm travelling by car, we stay in cheap motels. I take my own weighed oatmeal and some berries . Insulin or not I'd prefer not to start the day with refined bread and jam when I'm going to be sitting in a car all day.
The breakfasts are even worse in the hospital. The dietitian has a big input into lunch and dinner (very much plate method with half veg, 1/4 starch and 1/4protein, it's on the whole good quality ) She has none over breakfast They serve those horrible rusk like biscottes with coffee. Because I ate porridge pre diabetes, she got my OH to bring in some oatmeal, arranged for me to use the microwave and got a pot of fruit compote provided but I was the exception.