Well,
You're probably not going to take my advice on this, but here it goes anyway. Are you going to Provence to capture beautiful images, or to have a wonderful time with friends, and bring back some great memories? Because if your goal is the latter, you're better off with an absolute minimum of gear. Like one body and one lens, and make it a small lens.
Unless your party are all made up of photographers, it is going to get boring really fast for everyone else while you swap lenses and work shots. And working shots is great for getting the best possible images, but it isn't necessarily the best way to enjoy the experience. You don't want to be the last guy in to town in the evening, possibly late for socializing, exhausted because you're carrying too much stuff, and frustrated because your photographic expectations are too high.
I would take the X-T1, the 23 and maybe the 35. Or just the 23. It is a wide angle, and you can still do decent portraits and group shots with it. Set your expectations to capturing great moments and not spectacular images, and make sure you enjoy the moments. You can take amazing pictures anywhere, any time, if you've got the skill. But you're only in Provence for a few days out of your life. Don't let gear get any where near taking the fun out of that.
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If you're going with the intention of capturing prize winning photos and are hoping to sell or exhibit them, you should probably take all the gear you can carry. In a car.