We own a van that would be a 12 passenger if it were not converted. We only use it for vacations as a rule. It drives like a dream going down the interstate and I don't mind driving it a bit, but I hate to park it. I should mention that I normally drive a Subaru, so even our mini-van seems big to me. If DH drives a normal size car, he should be fine.
I still think things will be tight with so much luggage. We bought a Samsonite soft carrier for the top of ours for trips where there are all six of us and quite a bit of luggage. If those eight bags are large, some of them will be in someone's lap.
This actually isn't a terrible solution when renting a mini-van. We flew into Denver last year with the luggage carrier packed in a suitcase. When we got there, we selected a mini-van with an appropriate roof rack. We were spending the first night close to the airport, so we just crammed all the luggage into the van and got up the next morning to install the luggage carrier. It takes a few minutes, but sure beats piling luggage on top of the kids. When it's not needed, you can just throw it in a closet at your resort. It's been well worth the $50 or so we spent for it at the Samsonite outlet. After the trip, we put it back into it's box and throw it into a suitcase.
Sheila