According to the 2020 brochure, "In addition to or replacing Premier features, High Country includes:"I'll second that since I'm shopping myself. Premier is the new name for LTZ across the Chevy brand.
High Country just gives you a name plate on the back and embroidered on the headrests and some piping on the seats as far as I can see.
Most of the options are standard on both packages as far as I can tell.
Is that a different type of AWD as an upgrade? The reason I ask, the Premier also has an AWD option.