Well the 15 sensors are back ordered until April so I am going to go ahead and mount my winters on my new wheels without them and deal with the warning ever time I start the car. I will get them before I mount the winters next year.
Well the tires are all mounted and I will be putting them on the car this morning. I am not going to worry about the sensors now until after I take them off in the spring.
I had to do a patch/plug repair at 520 miles. Tires Plus did not yet have any data on the 2015 so they went ahead and used the 2014 tpms part. So far, everything appears to be reading correctly, I also tested with a guage to make sure the readings on the dash were the same. They did ask me to check back in a few months to see if they have any updates and would replace it at no charge if it is different. I have found it quite difficult to get a clear definitive answer on this subject as well.
TPMS sensors for the 2015's are back in stock at Late Model Restoration. $19 each with free shipping...best price around from my research. I am unsure if they will just sync up with the ECU or if you'll have to purchase/use the pairing tool. I didn't buy the tool, but I won't know the answer until I put the summer wheels on in a couple months.