The first sea ice outlook from ARCUS is now out. Have a look at the full report at the link. You'll see my name there, with what turned out to be a boringly typical guess. Actually, we all seem to have been pretty much of the same mind as to amounts, and to distributions around those amounts -- somewhere about 4.9 million km^2, with error ranges of about 0.5 million km^2.
The interesting part being that we arrive at such similar estimates for both value and variation around it by such different means. Do look at the descriptions of how groups arrived at their predictions. I'll spend more time here on my method later. The only particularly different guess (3.2 million km^2) was from a group (Arbetter et al.) that provided 2, and labelled the other one (4.7) their outlook prediction.