suburban as a tv for first tme

Good day. I have a 2011 Suburban LT with heavy duty towing package that includes extra cooling for oil, transmission, and radiator. The tow rating is 8100 lbs and tongue rating is 1100 as long as weight distribution is used. The max rating for everything: truck, passengers, cargo, trailer and its cargo is 14,000 lbs. We recently upgraded our trailer to a Keystone 287QBS, 32 Feet, 7200 GWVR. The trailer is around 5400 empty. I have a 1200 lb Equalizer hitch. A few weeks ago, we made our first long distance pull with this new trailer and went 1900 miles round trip. We had 3 kids and a toolbox that could count as a passenger. I wanted to have whole set-up weighed before we left just to see where we were at, but didn't get a chance to. So off we went. All was well for entire trip and encountered no issues whatsoever, other than fuel burn! The dash said 7.5 MPG average, but doing the math with fuel receipts was more like 6-7 MPG. and on some steep grades, was in 2nd gear at times driving 30 MPH. I was refueling in less than 200 miles to play it safe. Much less than when we went from Florida to Yosemite and back at 250+ miles per tank with our old trailer. Also: did begin to have messages and indicator stating that the traction control and stabilitrack system has been disabled, but was usually able to reset it. This only occurred while towing and caused no handling issues as roads were dry. Overall good towing experience and enjoyed the trip.