rheistand

Your 23 for low light or action shots and the 18-135 for multi-purpose and wide zoom range when you have good lighting, which should be most of the day on a bicycle. If you want portability and only 2 lenses, these are the two I would take for an almost entirely outdoor holiday. Another option is to use an XF18 pancake in place of the 23 but then you might consider just using a cell phone for quick, informal shots and keep the faster XF23.

For a week in the mountains I take single X-T1 + 18-135 and that's it. I want to stay light and don't want to waste time swapping lenses so 18-135 is ideal for such purpose.

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.

Bike is my main method of moving around, and I usually carry varying amounts of photography gear with me as well. I actually used to have the exact same set of lenses you currently have along with Samyang 12mm and 55-230mm. They're all great lenses, but I simply missed the convenience of a zoom while biking, so I recently sold the 23mm and got 16-55mm instead.
 
Nowadays I just tend to take the two zooms along if I go biking, and the rest only if I know I'll need something the zooms can't do (low light performance, better bokeh, wider lens). Constantly switching lenses is just annoying if you want to shoot something quickly. One thing to keep in mind is that 16-55mm may be too heavy for some of the smaller mini-tripods.

I would take 23 mm + 56 mm to trip. That is just enough to carry when you are cycling but covers well most of the situations.
 
I would even think about X100T. One well known Finnish long distance cyclist used to have heavy DSLR, but he has changed to X100S in the latest trip. 
 
http://jukkasalminen.com/varusteet/
 
http://jukkasalminen.com
 
Remember to take 2 extra batteries and some kind off small tripod. I have 3 extra batteries with me (X Pro1) and Sirui T-025. T-025 is too heavy for cyclist, but Sirui 3T series or Gorillapod would be perfect. 

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If you pack light, like 2 zooms and a small prime lenses, it should be sufficient.
 
Depending if you need to put more things in the bag like extra clothes of a rain coat, you might want to get the 15L version just to stay on the safe side.
 
Now if you already have the 10L version, no need to go grab a new bag. It will be a waste of money, I would rather work around the smaller bag and pack lighter.