Gregg, the A7 II is the most enjoyable camera out of the 3 bodies and the IBIS performs very well for me. I took 3 bodies on that trip although I didn't use the A7 II much since it was more my back up body after experiencing a failure of my A7r in my previous trips.
Except for shooting in the ice caves, when I used my A7r and for shooting the northern lights, when I used my A7s, the Canon 11-24mm stayed on the A7 II all the time. Although it is an ultra wide angle zoom, but I shot a lot of close up shots at low angle and admittedly (shame on me) I didn't use my tripod for these shots, the IBIS helped tremendously to get tack sharp images.