EFA Progress: Almost to Armhole

I'm taking a short break from EFA; almost at the armhole. Here is where I can add length to it, so I need to decide how much more length to add.
A close-up of the trees in the enchanted forest.
Right now it's 14 inches long and there are a few rows on the chart to go before the armhole decreases. I don't want to block the length out too much; I'm sure that would distort the proportion of the trees and other details too much. So I'll ponder a bit and decide on the right length.