Our family of 5 is much more comfortable traveling in 3-rows of seats. We towed our TT with 3 kids in child seats for two seasons before getting 3-rows. If your trips are under say 2h each way, just take two vehicles. Way cheaper than a new(er) tow vehicle.
You can find a lot newer 1-ton passenger van than pickup or SUV for the same $. I highly recommend a 2010+ GM van 6.0L/6-spd. I'd recommend our Suburban as well, but I don't think you'll find much for 2008+ 3/4 tons under $15k. But the only way to get over 10k RV tow capability with 3+ rows of seats is -05 Excursion or -06 Suburban/Yukon XL 2500 with 8.1L.
