Here's my story.
2010 21SS towed by a 2008 Chev Colorado. It was fine up to 70 kms all by ourselves on the road in perfect weather. Anything else it was beyond a handful. I almost ended up in the side of a tractor trailer once. Long expensive story short I bought a 2010 F150. I could relax on vacation now.
My dry actual weight was 4574 lbs. I figured 5500ish lbs loaded. I weighed the Colorado and 21SS together with family at 9850 and the trailer was empty.
My recommendation is to forget the 21SS if you stay with the Traverse. Go to something without the slide which will save weight.
Unfortunately, you love the 21SS. You are so close that you will not likely be happy in less than perfect conditions.