I replaced the front pads on our 2014 last fall (38,000 miles) and this past Thursday I replaced the rear pads and rotors at about 46,000 miles. In both cases the pads were in decent shape. The front were at about 40%, backs were fine. The reason I replaced the fronts last fall is we ski all winter in Utah and the road we take almost every day is steep, very steep so the brakes get a work out. Also I am not in a position to do much in the way of vehicle maintenance work where we live in Salt Lake City.
I am sold on Wagner OEx brake pads. They generate less heat, have shorter stopping distances, reduced rotor wear, less dust and will last longer. When we got home to WI last month I noticed the drivers side rear rotor was showing some uneven wear. I replaced the pads and rotors this past Thursday with Wagner rotors (and OEx pads) that have a black coating on all the non pad contact areas to prevent / reduce corrosion. The backside of the original rotors both had a great deal of rust on the area that contacts the hub. This corrosion can result in warping of the rotor so I thought why not go with a coated rotor to prevent that rather than having the old rotors turned. I have the towing package so the brakes are "heavy duty", the rear rotors are 345mm OD. I would measure to verify which ones you have before picking up the new ones. I bought both items from Rock Auto at a significant discount to what AA, O'Reillys or NAPA sells them for.
The rotors have a small locating screw that holds the rotors on the hub prior to reinstalling the wheels. One was frozen tight, had to drill it out. Before you try to take those out use plenty of penetrating oil especially on the back side of the rotor where the screw protrudes. Good luck