Thank you for all of the feedback. I appreciate it and found it just what I needed.
Just for clarification:
In regard to luggage, that's not an issue as we won't have any when we pick it up.....sounds funny doesn't it?
We are there for 18 days. When we start out we are flying down from DC as a party of 6 (4 adults and 2 kids (6 and 9)). We have a minivan reserved for the first 10 days. Got a great price with
Alamo for $299 total after taxes. We do the cruise, then check in a the BCV. The weekend that the big kids and grandkids leave, we turn the minivan back in. Both parties reserved the standard SUV with National and are taking advantage of the "drive out of Florida deal" ($9.99 per day (full size car) or $19.99 per day (SUV)). My daughter&husband/2 kids will drive home the next day and it cost them $49 total for 3 days to drive themselves home and return the car to Dulles airport, which actually gives them time to stop over night mid drive if they want. Since the family leaves a week before us, we decided to take advantage of this deal too (we've never driven home to the DC area before) and we didn't really need to tool around in a minivan for the 2 of us. So we will have the SUV for 10 days, but at that price it's still a good deal, considering we didn't have to pay for airfare too. My total price was $184 after taxes/fees and discounts. Which is cheaper than it cost for the 2 of us to fly home. (Obviously since we are both retired we don't have to worry about time--we leave WDW on Sunday May 18th and don't return our car to Dulles until Wednesday May 21).
So all of the info sounds like my daugher & SIL with the 2 kids should be comfortable, and should accommodate their luggage for the drive home. They drive a pathfinder at home, so sounds like it should be similar to that.
Since we pick up the SUV on Saturday and the family leave on Sunday, we thought if there was a 3rd row seat, we could all pile in one on Saturday night and Sunday when zipping over to the parks instead of having to both drive those last couple of days. We don't need the 3rd row seat. But it would be easily to take 1 car.