It's easily big enough, but I doubt you can heat it warm enough, even in south france. 35k litres (9500 Gallons) is a lot of water.
It's true, that's why i'm considering to convert it in"indoor pond", my wife is close to agree !! she became to ask me to see the different Big Cichlid !!
If i could close the pond, it would not be a problem to warm all the water for me.
. A huge amount of chlorine later and I have a swimming pool again. All of the pond filtration is still in place and I will turn it back into a pond someday when this drought ends. At this point it will take at least a year of good rainfall to replenish our aquifer enough to support running the pond again. It sucks but mother nature always wins in the end. All I can do is wait. They say this type of drought only occurs here once every 50-60 years so when it finally does come to an end things should be good for the rest of my life.