I saw some on the way home Friday night. We were coming in for final approach, so we were only a few thousand feet up. I always enjoy seeing them.
Best is to be going west. As you cross time zones, you can see many more.
BTW - during the flight, the a/c shuddered a bit. Not much, just one of those quick things. It brought to mind the father of a friend of mine. He was a waist gunner on a B-17. I imagine he felt more than one "shudder" and the fireworks he saw were probably a lot closer!