I heartily agree with Bob on the replacement ride. Ask for one since it's a problem thay can't find the answer to and have bumped it up the chain.
This is easy to say because it isn't happening to me but it appears to be anomalous situation given the number of '14 and '15 RTs on the road. Two or three or four or a half dozen that we know of is not cause for alarm IMO, especially since changed thermostats have solved some problems. YMMV.