At least, I estimate the progress to be at 30%.
Thus far, the blanket is shockingly small. The centre bit is only 14 inches wide, and will be roughly the same height. I'm planning on blocking the ever-loving crap out of it to make it a reasonable size. Because to me, right now, it looks like a slightly larger than normal hankie.
I have most of the middle done. I haven't even used half the yarn yet. This bodes well.