I believe you are all worrying a bit too much...
Remember, the entire drive train (including the ICE) comes with a 10/100 warranty, so unless you're putting on massive mileage, you're covered - at this point, we are all covered for a lot of miles/years.
Since the Niro is a new model, WE are Kia's guinea pigs - or, if you prefer, Kia's canaries. This is, in reality, a part of being an "early adopter" (owner of a new model). We are the beta testers. We provide the data points for Kia to debug and improve their work.
Expect some bugs to be worked out. All new models have 'em. So far, the Niro's issues seem to be pretty minor for the majority of owners.