If the blades are sharp, you should be able to cut it in no time!
I fished the big lake in NH this past weekend and used my 8" hand auger to cut holes in 20+ inches of ice.
As long as you have the endurane and stamina to cut numerous holes (you WILL be leaning over as you cut), you can do it.
Of course after cutting 2 holes I felt like I could tear a phone book in half.....and then exhaustion hit me.
Seriously, 16" and a hand auger is completely doable. It will be tiring if you are planning on moving around and cutting many holes, but it is doable. If you are going with others that are physically able, let them get in on the "fun" and cut a hole or two?