Update: We picked up the car last Friday(Jan 02) and I had the dealer install the Goodyear eagle ultra-grips on the car before delivery. He also ordered my a set of sensors for my "summer wheels and tires" , but he was told by Ford that they wouldn't be available for 6 to 10 weeks due to "production demands". In other words, the supplier can't keep up. So, when they become available, I'll install them myself, and just have the summer set re balanced.
Don't wait until summer, you can use sensors for a 2010-2014, they work as well. I know the 2015 design is different, as in smaller and more compact, but the previous version are compatible without re-training needed. I know because they are on my wheels/tires that were on my 2014 GT before I traded it in for the 2015.
FYI - the TPMS sensors potentially saved my life one day. It alerted suddenly after hitting a small object on a rough piece of highway. I thought I had just rolled over it, as with the the low profile tires everything felt fine, but about 2-seconds later the Tire Pressure Warning came on. Fortunately the TPMS technology did its job and alerted me quickly, giving me enough time to safely move to the right, slow down, and exit the highway. When I stopped I discovered a completely flat and blown sidewall with a 3-inch gash.