Eleven departments remained on orange alert weather warnings late Saturday.
A 70-year-old man died in the Pyrenees-Atlantique in the Basque Country on Friday when his vehicle struck a fallen tree.
In Espiens in the Lot-et-Garonne region a 76-year-old man was swept away by rising waters when he went out to fetch his mail on Friday.
Rescuers found his body 24 hours later more than a kilometre from his home.
Five other people were injured, two seriously, when trees fell on their vehicles.
As many as 40,000 homes were without power on Saturday afternoon and some 15,000 remained so by the evening, electricity utility operator Enedis told AFP.
A company spokesperson added some 2,000 technicians had been deployed to restore power to those customers, urging people to call a dedicated hotline if they saw power lines had come down.
Overnight, some 400,000 homes had suffered power outages as floods inundated parts of the region with waters rising to up to nearly nine feet (2.7 metres) and by 30 centimetres per hour in some areas.
Flooding and landslides cut off access to the skiing stations of Gourette and Artouste, while the distribution of drinkable water in the commune of Laruns was interrupted.
In the nearby Landes department, about 600 people were evacuated on Friday as a preventive measure in areas where the Gaves de Pau and Oloron rivers converge.
“We are getting used to this now,” a weary pensioner who gave his name as Christian told AFP.
“We put everything on the upper levels, and we clear out everything from the garage,” he said.
But water levels were slowly falling in the area, local rescue force commander Olivier Loustau told AFP, and clean-up operations would probably start Sunday.
The Alps, where weather services had warned of heightened avalanche risk, were earlier downgraded from the orange alert level, as was upper Corsica where winds had been packing speeds of up to 150 km/h.