Q: IPhone 6 plus screen frozen with flicker at top of screen

Over this past weekend, while out of town for a wedding, my Iphone 6 plus touch screen froze during normal usage.  Since touch screen was unresponsive, had to hard restart phone using button on right side and home button.  Was responsive for a few minutes after hard restart, but then would go out again.  Also noticed a flicker to top of screen during this time.  Now, cannot get it to work at all anymore.  Attempted to "restore" phone through ITunes, but since I cannot enter my passcode with touch screen could not do.

I have become aware that this has been happening to other people with my same phone model and wonder if this is a product defect similar to the camera defect on some of same phones?  Have appt at Apple Store tomorrow, but worried because I am past my 1 year warranty time frame.