Ah don't lose your confidence over potential snobs, earplugged. Just my personal opinion but I always think it's far more impressive when someone cooks from their place of comfort, competently and confidently rather than going overboard and pulling out all the culinary big guns they'd otherwise never touch with the clear intent to impress.
The produce is great there, keep it simple and let the quality ingredients shine would be my strategy. It's going to be hot, you're going to be tired by the end of the day so just cook simple tasty things that are bang in season, get in lots of fresh herbs, good olive oil, etc. If you're on the border with Italy I'd definitely go shopping there, especially the markets. The fresh homemade mozzarella is amazing there. I personally prefer Auchan over Carrefour but usually, you're destined to shop whatever is nearby anyhow.
Things I'd cook would be, puy lentil salad with dijon mustard vinaigrette, capers, and sauteed cod cheeks (which are quite special and usually dirt cheap, difficult to get here but not so much in France IME, can swap for scallops, regular cod, or even poached eggs) with lots of flat leaf parsley or sauce verte/salsa verde, serve with some crusty baguette or boiled little ratte potatoes tossed in a bit of of good butter and chives (or flat leaf parsley) or the good old standby radishes with butter if you want to keep it lighter.
Burrata with lots of lovely varieties of special tomatoes, lots of basil olive oil, a good balsamic, good amount of seasoning, serve with a good focaccia if you can find some.
Nicoise salad with the lovely little ratte potatoes, fresh lightly griddled tuna, remove the skins from the tomato if you want to be a bit refined about it.
Spaghetti Vongole always easy, tasty, and quick too. Watermelon gazpacho with grilled prawns. Grilled fish with sauce vierge. Stick some peaches in alu foil with a bit of honey or sugar and let them warm through, serve on some vanilla ice cream, etc.
Not really French cooking but in the simple but tasty corner the thing I've been repeatedly making this summer due to repeated requests is this Mint, lime and tamarind sauce that I splodge on anything but my favorite combo has been with a 'caprese' (with apologies to my Italian ancestors) of grilled white peaches and buffalo mozzarella. You might need to travel with a jar of tamarind paste though, not sure how readily available that is over there...
And with that I think I killed my just keep it simple rhetoric
I promise the other stuff is quick and easy with little effort. Well at least to me, I'd advise cooking whatever version that is for you. And I'd probably make Auld's passion fruit punch for impression points.
peregrane, depending on the shape I wear a strapless bra or I have sort of silicone paste on things. They basically form around your breast (mine are pretty simple, just there to obscure the nips but there are more elaborate ones that give lift/keep them in place and/or more volume and there also ones that fit only cover the nips) they feel a bit odd for a minute but they adjust to your body temperature and then you sort of don't notice them. I don't recommend them over 35 degree weather though 