What time of year do the carp spawn?
Spawning time is purely a matter of water temperature and mostly late May or June is the spawning period in France. A warm spring or mild winter can bring it on early (I’ve even known them start in March) and some lakes will start sooner than others just because of the volume of water in them means they are quicker or slower to warm up.
Similarly a colder spring may see the spawning dates pushed back later in the year.
If the water temperature is maintained long enough to see spawning through properly then all well and good but if the temperature drops and it’s halted spawning can occur up to several times over several months. So nothing is ever guaranteed.
On a better note carp generally feed really well both going into and coming out of spawning. So even if your week is affected, you would be very unlucky indeed to have it exactly co-incide with every day of your holiday.