Most states you can legally ride back in the 5'er going down the road. I understand your seating issue.
We actually had a tight traveling timeline to get from VA to CA for my husband to do some training before a 6-month deployment and we chose to come with him and live in our Seismic for 2 months. We had to make it across in less than 4 days...and that is TIGHT with a family and RV. We only made it because we would take shifts driving while the other was sleeping in the master bedroom, or at least relaxing watching some tv with the kids (giving them a break from numb butt sitting all day).
2011 F-350 DRW FX4 Crew Cab, Lariat, Platinum
2012 Jayco Seismic 3914
2011 Jayco 32BHDS w/outdoor kitchen (LOVED IT)
2006 Jayco 31BHS (Our first camper!)