Holy Cow! A recent trip? I was in Iceland in February this year, and the weather never allowed me to even see this with the naked eye! Congrats on being there at the right time.
I have heard stories of Japanese tourists that have traveled at a cost of $5000+US to "see" the Northern Lights - only to see nothing.
We got very lucky! We touched down on sat 28th Oct, had enough time to get to the hotel and get a bite to eat before heading out. The Aurora started off as nothing more than a dark greenish cloud, but over the next couple of hours is blossomed into the all-singing all-dancing Aurora you see in professional pics and films. Simply awesome.
Went twice again to see it and were lucky again, but not in the same magnitude. It really is down to luck - cold, still nights may be not exactly in short supply, but solar activity that happened five days before to have made the trip down to 66 degrees north in time for it to light up the sky? Not so consistant.
I have something like 50+ Aurora pics. Some are great as is, some I'll be editing to remove house lights/car light time lapse streaks. Will probably post some on here!