My experience is also limited.  I was fortunate to go through the NWP in a low ice year (2011), and I've only been to Antarctica once, so have no experience to compare it to.  

Similarly to what you said, what's important for voyaging isn't so much the total amount of ice, as where the ice is.  That is determined more by wind direction (pushing ice towards or away from routes) and speed (higher winds causing more waves breaking ice into smaller pieces which melt faster), and currents (moving ice that is not attached to the shore).   

From the perspective of planning a voyage around ice, I don't see the overall process changing much.  In some years some areas will have little or no ice, and some years those same areas will be difficult.  The conditions one will experience on a particular voyage are not likely to be more predictable.   

I have been asked to write a section on the impact of climate change on Arctic Sea Ice for a new guide to the Viking Route.
I thought I might expand it a little to look at the consequences for high latitude sailors.
My own experience is limited compared to others so I have cast the net among some of the more seasoned skippers and have already had great feedback with more to come.

I have plenty of images highlighting glacial retreat in both polar regions but would like to get some thoughts on the impact for high latitude sailors.
In my limited experience of the Antarctic Peninsula there was a lot more ice in the water in 2018 and less on the coastal fringes than was seen in 2007.
My own NWP transit took place in a difficult year with only one route opening for a short period so I also suspect that the break up of the Arctic Ocean sea ice is allowing more ice to flow south and so even with less multi and first year sea ice the routes in the NWP and on the east coast of Greenland can still be problematic in recent seasons?
I have quite a bit of scientific data but I wanted to try to give an understanding of what it means to the High Latitude sailor.
Impact on navigation, areas where access is now open / closed. Impact on wildlife to be seen, etc.
I am contacting a few of the more experienced high latitude sailors to get their input.
What are your thoughts?