WE used to have a c4 grand picasso and when we had 6 we had to use bungys to pack all the luggage etc to the roof and to the one side and it was the case of taking the stroller buggy as it’s smaller.
Most of the time we only had 5 people in the car so was ok but when it was 6 it was tight as the two other seats are in the boot. so as alan said maybe the Vivaro which has 9 seats so should leave lots of space for luggage and stuff. The ap ain’t to bad on the Manuals.
One could get also get a roof box i guess.