Well, based on the helpful feedback received here on my post, I did decide on getting a Yukon XL with the Duramax.
For the last several weeks, I have searched day and night, checked the GMC website daily, and found a couple of Premium/Luxury-package equipped SLTs I liked, but none were quite perfect enough in regard to options and location--I didn't necessarily want to deal with the logistics of buying all the way across the country, since I would want to see/drive in person prior to making the purchase.
Then this past weekend I looked at and sat in a Denali, knowing right away that I had to have one of those instead. I looked for a few days for a Duramax-equipped Denali, and quickly realized that the combination of options I am seeking is even more of a unicorn in that trim level.
So I just placed an order yesterday for a 2024 Yukon XL Denali with Duramax and just about every option except the Rear Entertainment and Max Trailering packages...I don't have kids to entertain, and won't ever buy a boat or camper.
Waiting to hear back about when my order will actually start being processed, and roughly what to expect...2-3 months, 6-8 months, who knows at this point with everything going on?!?