The sea ice has much to do with ocean currents which bring warmth from the tropics to the polar regions. Typically, more warmth flows either to the Antarctic or arctic depending on ocean current decadal cycles. From 1979 to 2023, the Antarctic ice gradually increased while the arctic gradually decreased.
The prediction from 'green' groups was that both would decline by a very large amount. By now, arctic sea ice is supposed to be gone in the summer. The Antarctic should be melting rapidly as well as Greenland such that sea levels are increasing at an ever-greater speed.
But sea level increases are about the same as they have been for over 100 years. A slight increase every year.
During the Medieval warm period, many areas that are covered by ice and glaciers were not. This can be seen by wood and tree stumps in areas that in the arctic along the coast that are too cold, and ice covered for trees. Also, some of the Viking settlements in Greenland are now just emerging from the ice. In the Medieval Warm period, Greenland settlements were able to grow crops, grow hay in the summer for animals and there were even trees for firewood and building. Later, everything died, a few people were able to leave Greenland and the rest starved to death or froze to death. The Viking settlement areas are still too cold with permafrost to grow crops or trees. The harbors the Vikings used then are now too ice covered to be used.
However, the temperature is recovering now from the Little Ice Age and may recover back to temperatures common in the Medieval Warm Period.