I will tell you what my dad always told me, not that you asked or it is my business. Buy with your head, and not your heart. I have an 04 Z-71 Hoe just like yours. I love it. But let me break it down for you from my experience, and its true as sh*t-
I was 18 years old, bought a 85 MR2, had it 1 year and wanted something else. My dad told me to think of what I wanted if money were no object, duh, new 911 turbo porsche. $135,000 was to laugh at for my age.
After that from 18 till I was 26 I bought and sold 23 vehicles. Some trucks, some were sports cars like late 80's vettes, mr2's etc. I was a Physical Therapist, but quit and started my business when I was 27. As part of my "business lesson" from my dad, he asked me if I wish I had my porsche, I asked him what porsche. He said the one I should have bought but couldnt afford. I was clueless at that point. He figured out how much I had spent on my vehicles I bought and sold, money earned and lost, interest paid, interest lost, appreciation and depreciation, and showed me It would have been cheaper to buy the porsche at the start by about $28,000. At that point I had a newer Dodge dually I owed money on.
When you trade like that, you always lose big, no matter if you have perfect credit. The only way to do it is if you can trade for a new vehicle with 0% interest and you get a good trade deal. Even thats very rare. The only reason I say this is you mentioned you loved your Hoe, and would only trade for what you wanted, a Denali. Then you jumped to an Escalade. I know they are not all that different, but I see myself in you. My opinion, keep what you have and if you can sell it out right, sell it if you want. Now you can negotiate your price. When you trade, you never really can. You might buy the lade, and it dies and costs you $4500 to fix it. Will you fix it, or have to let it sit. Id spend a few grand and modify your 5.3 and beef up your tranny. It will be much cheaper, much cheaper in the long run. Add 75 hp nitrous for a few hundred bucks, then how far off will you be from 6.0 power? AWD is nice in winter ,but auto 4wd is too. AWD sucks gas too, and costs way more to fix. My 2 cents. Good luck with your decision, and remember its not the payment you have to worry about affording, its the interest and total cost added to the new loan.