We are out in Florida at the moment and have a Tahoe. Even though there are only two of us we always tend to book the 7 seat SUV from Alamo and generally get a Tahoe as we like it so much. We come out a few times a year and we have been lucky enough to have been upgraded to Suburbans at no extra cost on our last couple of trips. These are essentially longer versions of the Tahoe. Each time the upgrade has been given to us in the parking lot without asking but you certainly can't rely on getting this. When we picked this one up at MCO 3 weeks ago we were offered an upgrade to a Suburban for $19 per day but declined. My advice would be to book the car that's right for your party and anything extra you get on arrival is a bonus.

I took a picture of the rear space in the Tahoe this morning when I saw your post.



The picture shows the 3rd row of seats folded down leaving seating for 5 inside. Although it's a very large SUV, I'm not sure you are going to get 5 suitcases in the available space with the number of passengers you have.

If you really want an SUV with extra space I think the Suburban or Ford Expedition are the only ones that fit the bill. We've had both and they certainly offer more room. In the past we've also had Navigators and Escalades but have found they are much the same size as the Tahoe with a bit more luxury.

Hope this helps.