We also booked the 11-day Norway/Iceland cruise yesterday (June 29)!

We hadn't planned on going back to Europe next year, but this is one area of the world we have had on our "wish list" for quite some time, so we booked it and will figure out how to make it work!
No, you will not be able to see the Northern Lights in June... it'll be too light out. It'll be really light the whole trip... lots of sunlight the farther north you get. I grew up and lived in Alaska for 20 yrs, and Alaska is about the same latitude as Iceland, and there is about 20 - 22 hrs of daylight in the summer!!!

You can only see the Northern Lights in the winter, when there is about 20- 22 hrs of darkness!