I did it!
The center line is where I cut:
I spent a month and 8 skeins of yarn on this sweater. I pulled back rows when I made mistakes, even when it meant going back and destroying an hour or more of work. I scrutinized the cables for errors. I redid the colorwork at the top THREE TIMES because I messed up (I don't read charts well). I actually used a row counter on the arms so they'd be exactly the same length, instead of winging it (which is what I do with socks). I drank the same amount of brandy when working on it, so that my tension and attention would remain the same. And now I have to cut it?!
I loathe the bathroom-shot, but it's the only mirror in the house. Overall, the sweater is a bit large -- one size down would have been ideal, but I don't mind it as it is. It is excessively warm (Cascade Peruvian Highlands Wool) and I took it off as soon as I was done photographing it. Like nearly all of the posters in the Ravelry Big Girl Knits group, I'm not fond of the neckline, but I am so happy to be done with the sweater that I'm leaving it as is. The button band was easier than I thought, and looks pretty good, I think, except on the K rows bottom and top where it rolls up a bit.
Side note: I had a heckuva time with the sewing machine. I spent literally ten minutes trying to figure out how to drop the foot. Literally. I almost called a friend to help. I couldn't find the instructions for threading bobbins, so I had to figure it out on my own, but I didn't tangle the thread and everything worked fine. It was overall very easy to do, and I'm very glad that I did a project that required learning new techniques. And now that I know how easy steeks are (for this project, anyway) I won't shun other steeky projects!