After I booked the room, I asked Sébastien for an earlier check-in (on his page it was mentioned as “flexible”). I got an answer after 48 hours. He organized an early check-in “by courtesy”. I was a little bit surprised to be honest. However it worked well with the handover of the keys from his sister.
The accommodation was quiet and comfortable. Ideal for getting quickly to the center of Merignac or the center of Bordeaux by car.
The toilet is on the ground floor. But for me nothing critical!
I fed the cat “Ciska”  However the was so hungry that she opened my door in my absence and have eaten a little bit from my bread which was on the desk in my room. Also no problem for me 
The bed was a bit too soft. The heating is so small that it is not enough to warm the room completely. It could be a bit warmer ;)
In total I can recommend this apartment.