I used to be a navigator on a very large cruise ship that cruised to the Antarctic several times a year, I absolutely adored the Antarctic but we had some very very close encounters with icebergs. Determining current and drift is incredibly difficult, so collision avoidance with the ice is done visually. Occasionally it is possible to underestimate or misjudge the amount of set pushing you into the ice. The ice pilots that are assigned to the ships are good, but generally its just one pilot who isn't around all of the time, and even they don't have any extra tricks for determine the current.
Whilst regulation has increased for vessels operating in the antarctic, I wouldn't be surprised if in a few years only the very hardened small ice class cruise vessels are left operating there.
As for earlier comment about lifeboats, there will be sufficient capacity for all passengers, and including the life rafts the lifesaving capacity will be 2:1.