Where did you find that info about the single-day line-up? I haven't seen it on PB site yet. I was wondering about Greensky too.
Using the classic technique of looking at individual artists websites.
Greeensky was the only scheduled artist that I could find has 3 dates in a row in Telluride. Not sure if that's just how they put it on their site or if theres possibility of nightgrass. Everyone else that listed Telluride just had single dates listed.
I would guess that Greensky will headline Friday night, Infamous Stringdusters Saturday night, & Dierks on Sunday.