It depends where you are going as to whether you will be able to get the bread mentioned. There isn't a single shop that sells it in the whole of the departement I live in .
If you are eating out a lot; as you tend to be on holiday, then the large main course salads are often a good option Personally,(and am T1) I don't find any particular problem with the dressings . .
I find that main courses in many every day restaurants often come with far too few veg , often very overcooked haricots vert. It's often better to get a menu of at least starter and main course since you may get more veg/salad with the starter. You are also less likely to get the chips with everything which can sometimes be the case at some brasseries (Steak frites etc)
I find that portion sizes are often much smaller than in the UK (though I think that they are bigger than they used to be).
The markets are definitely the place to shop for veg and fruits; meat, fish, charcuterie and cheese can also be bought (but can be more expensive than similar products in the local supermarket) And as the previous poster noticed, delicious rotisserie chicken I really notice the seasons in the market here, this time of year fairly bare since not much grows but then from the first asparagus onwards you notice the changes as each thing comes into season
On the vexed question of bread ( remember I'm a T1 not a T2) I don't normally eat croissants or the typical semi industrial baguettes but there is often little else on offer in some hotels, particularly the ones you might use when travelling; solution don't take breakfast in the hotel.
I do eat 'in moderation' some breads ; I get on fine with many 'nut' breads, multi cereal and with the local sour dough bread These have a far lower GI than what we think of as 'French Bread'.
Do remember that on holiday you may well be doing more exercise than usual, I have been known to plan a day on holiday to involve a long bike ride or a lot of walking with a stop halfway for the sort of 'treat' I wouldn't normally eat. Actually some of the patisseries from the specialist shops,though definitely not low carb aren't nearly as high in carbs as you might think. ( often small anyway and if you choose carefully, not too sweet )