Where have all the good Tow Vehicles gone?

I just bought a 30' Airstream Bunkhouse, I have 4 kids and lots of stuff. They stopped making Excursions in 2005 and stopped making the 3/4 ton Suburban in 2013. What's a family guy like me to do? Ever drive with 4 kids jammed in a pickup? I have a diesel Excursion now but it won't last forever. I know there are conversion companies but that's seems a bit extreme. It's surprising there are no big SUVs left up for the task. 3/4 ton with diesel that is.