In 2021, when I was looking for something very specific (new, Longhorn, 6'4" bed, Delmonico Red), I found exactly one in the country: In Idaho, and I'm in Georgia. I considered flying out to buy it, but ultimately ended up ordering new from Mark Dodge.
When you say they drop $20K the first year, I assume you mean from MSRP. But no one should pay MSRP to begin with, so ordering new isn't as expensive as you might think. Expect at least $10K off a Limited order. Granted, $10K isn't $20K, but ordering new is the easiest way to get exactly what you want, if you can wait and have it fit your budget.
This
Autotrader search shows 133 new and used trucks that meet your criteria. Some of those are actually Limited Longhorns (flaw in Autotrader's search, apparently). Currently, it's turning up only
4 used trucks 2023 or newer. Some of the new trucks are around $16K off sticker. If you like the idea of a High Output Hurricane, those might be appealing to you.
Good luck with your search. Once you find what you're looking for, you should totally
buy my Retrax cover! (Nothing has made me appreciate the rarity of the 6'4" bed like trying to sell a tonneau cover).