Try this one at Auto Anything. I picked one up for my 2006 Tahoe and use it everyday in Florida. Makes a massive heat difference to the interior along with 5% tinted windows.
It says it fits all Tahoe models, even when selecting 2015 in the drop down menu. I believe it is pretty universal. Has a small cut out to fit around the rear view mirror, velcro strap to secure when rolled up and super shiny aluminum metallic surface to reflect the sun and heat. The fit on my windscreen top to bottom and side to side is spot on, with just enough at the side edges to tuck between the windscreen and A pillar.
10% off sale going now. Had mine shipped for $34.99. There is one model step up listed, not sure what the difference is.
Here is the link. If it doesn't work, just enter your truck details in the drop down menus. May be worth checking out. No complaints my end.
http://www.autoanything.com/driving-accessories/60A4065A0A0.aspx