If u own GM now usually get loyalty pricing. GM credit card points. Labor day good time to buy out of dealer stock. I non rev'd out of local area to make the deal. But found/got exactly what I wanted.
bought new in 2017 around this time ended up at $40K from a $55K sticker. Sold the 05 for $10K on craigslist. So it all worked out ok.
Id guess you could strike a pretty good deal all by yourself on new truck with all thats goin on.