I don't think you are going to get that low right now.
You may find a dealer willing to order for you at invoice...unlikely to find a Tahoe/Yukon/XL/Suburban on the lot at that pricing right now. Perhaps in a few months...
I had a "promise" to order me one at invoice in late summer 2021 from a dealer in Minneapolis. They said they were doing that for sold orders, but for inventory vehicles, they were adding $5k market adjustment. Logic was that for each 2 allocations they ordered sold, they received 3 more; so selling 2 at invoice enabled $15k profit. I was really close to ordering from them, but chose my local guy instead. Worked out for me, commited to the purchase on 11/16/21; vehicle was in my garage on 2/11/22.