Its funny because I got so many different answers regarding needing and entire new track vs splicing in extensions and reusing the old track. In my case my original door setup consisted of extension springs with the typical overhead opener and the door was 9' up. My new ceiling height was changed to 12'6" and we ended up moving the track up ~40" IIRC.
I just looked through my phone and this is the only picture I have that shows how it turned out. As you can probably see from the picture the door is tucked up really tight to the ceiling exactly how I wanted it to be. The guy reused my old tracks and spliced in a straight section to give the added distance. All that he added was the torsion springs the drums new cables and the opener. It's been about a year now with that setup and I love it. The door opens silent and very smooth, no complaints whatsoever.
I can snap some more detailed pictures if it would be helpful to really see what they spliced in.