I didn't see many repositioning cruises for sale. Only a few for Charcot that were quite long (e.g. 2-3 weeks) with zero stops. No thanks! I assumed they offloaded part of the crew and sailed with minimum manning. Do you mean that the repositioning cruises are "free" when added to the first/last cruise in a region? Wonder how many people are actually on the boat with you!
If I recall correctly, the sisterships are "ice hardened" but only the Charcot is an ice breaker. We had a rough return through the Drake on Le Boreal ... I couldn't imagine doing it in an even smaller Explorer class ship.
Abele 1757 was free flowing throughout the day.