My players managed to steal the thing, kill the beast, and kill the bad guys (wolfpack included) without breaking much of a sweat. The party has a cryomancer who can control the thing.
Obviously, moving forward, they'll be increasing frequent and nasty visitors in the night as the sphere does what it does. I imagine my players will get rid of the thing before they break it.
Interesting adventure and a nice doorway into higher level play. Now I need to find what lands from New Vinland the players will be gifted for saving the princess. perhaps this can lead into some political stuff with the Vikings.