Here is a problem of not knowing the shape of the earth

If it looks like this, then there is a LOT more ice possible at the south pole.
And maybe the sun course moves further south, and then melts more of Antarctica.

(where the sun path in the sky crosses below the equator)

Further, if the water isn't sitting on top of earth, and instead both the earth and the water are floating together, than ice leaving an area causes it to rise (as some places in Alaska) and we do not really have any idea how that dynamic will work.

Maybe the ice sheet that will cover Canada will push America down so the shores sink several meters...

no knowing