Important to remember.
Max tow ratings are based on curb weight of the tow vehicle. NOT the GVWR.
You usually have a choice of maxing out the camper and driving with only the 150 pound driver in the TV and your family and dog in a car following you; or maxing out the Tow vehicle and towing an empty camper.
If we have said it once we have said it ten gazillion times; salesmen LIE
It is their JOB
to get you into the most expensive; biggest camper they have on the lot that they think they can convince you that you can afford and tow. Note the word "convince" because they really have no idea.
Search on Suburban and you will find a recent thread where we did a similar workup. It was not pretty. With his family and some camping gear on board the maximum tongue weight available was 199 pounds Yep, 199 pounds as he weighted 7000 pounds "ready for camping" and no camper.
At 12.5% tongue to camper ratio, that made the biggest camper he could to max in at 1592 pounds. (What your tongue weight is on that camper)
If I were you I would be looking for a good lawyer.
Yes I know you have an avalanche but they have similar towing specs.
GVWR Scared Now
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW