I would caution you for warranty reasons to ensure what ever oil you use is certified to meet Dexos1 standards. Here is the latest list that I can find from GM Site: dexos1 Brands | GM
My recommendation as well would be to change the oil & filter at 7000 miles period, as god only knows what condition the friction modifiers are in after that.
I would also consider the fact that the oil filter may not in the best of shape at some point as well. Oil is cheap, engines are not. The oil life monitor is a guide.I would keep a record in the car of the last oil change, so u always know how many miles are on that oil & filter, just in case u accidentally reset it...ask me how I know...
I would never buy into the hype of 20,000 + miles intervals that is just wrong. You would need to change your filter numerous times in that process and with proper oil analysis along the way at 5 k mile intervals for safety reasons.
Common sense dictates a clean engine oil provides for a clean interior & longer life engine. A dirty oil provides for sludge build up, carbon build ups, sticky pcv valves, and leads to oil filters that can fail you in filtration department. Not worth it in the long haul... IMHO.

I got the oil changed in my '12 Cruze at around 6,000 miles, and, my oil life on the DIC was at 40%. I'm going to take it further this time, since GM & Chevrolet call for the Dexos1 to be used in my Cruze. As soon as my "change oil soon" message comes on, then I'll get it done.