That sounds like a great road trip! Fortunately, you can flat tow a 2018 Jeep Grand Cherokee, provided you don’t have the rear-wheel version. The rear-wheel-drive Grand Cherokee requires a flatbed trailer to tow.
However, if you have the 2018 Grand Cherokee with either four-wheel-drive Quadra-Trac I or II or Quadra-Drive II, you can flat tow the vehicle. The easy way to check to see if you have these four-wheel-drive systems is to look for a 4-LO gear. If you have this gear, you should be good to go.