Thank you all for your replies, they are much appreciated.

I had thought about a minivan rental, I guess I was just a little apprehensive because I have rented a minivan in the past and turned out to have underestimated how large our bags would be, and we ended up having bags stuffed between people. That was with 6 people, however. Five people might be easier with the ability to fold half of the back seat.

I think my game plan is book the Tahoe, hope for a Suburban (I will have several hours between when I arrive at MCO and the rest of my party does, so I can even wait around for one to show up, assuming they will even allow it), and if all else fails, head over to Dollar.