For just one night, it seems that you are not very welcome here. We had to park outside the barrier, even though we arrived before 6:00 pm - supposedly because it would be a rip-off otherwise. The night cost 14€ for 2 people, plus 1€ for electricity and 1.95€ for very poor Wi-Fi (0.50mbit), but we were allowed to use the (very clean!) sanitary facilities, which were quite far away, but not the water and waste disposal (that would have cost an extra 5€). There was plenty of space on the campsite, which really annoyed us. The bread service was good. A good alternative for one night is the pitch on the north side of the lake, if you are self-sufficient.