After soaking in much info from everyone on ExPo, here's what I came up with (credit to the Portal for good ideas; bad ideas are the responsibility of the owner):
My wife and daughter, for some reason, just don't find camping in such fine quarters appealing, so a $200 Tentcot seemed a better choice than a more expensive and larger RTT. My 12-year-old son can fit across the rear seat, or we can toss out a small ground tent he uses in Scouts.
Rear cargo setup should be in tomorrow. Once everything's in, I'll be testing it out at the Toys-for-Tots trip next weekend and then posting more details.