When I was single without a worry in the world I would over tow all day. I have, as much as twice the trucks GVW.
Now that I have a family I would get a new Tow Vehicle. You can, and people do make there trucks tow more than GVW every day. Safety is number 1, and if you have an SUV I am sure you have passengers.
Now that being said, I have a 59 chevy I have pulled over 10K LBS. GVW 5K. From California to Oklahoma. Video below.
I installed a good trans cooler, brake controller, wiring, sway control. And I have 3.38 Gears. Pulled the 3.90 So I could go 55MPH.
https://youtu.be/_cNYP2aY19Q
Hard to give advise when I have broken the rules ( I was younger ). But that's my experience. Take it for what its worth.