What am I Thinking?

What the--?

Ok. So in a fit of something yesterday I got out this huge ball of Rowan Big Wool (4 skeins - i started making myself a Tomten from it and then frogged it all into one giant ball) and decided that the Mole must have a black garter cardigan immediately. I decided a simple, jackety drop shoulder with zipper would be best.

My big needles are all Knit Picks Options and I could only find one 15 and one 17 but I was able to find both 13s. So I used those. The fabric is dense, but actually fine for a fall jacket.

But now that I see the back complete, it's a bit stiff and I'm thinking a modified drop shoulder would be better. Then I thought - why don't I just make a Tomten? I had planned on making the Mole a Tomten with legs out of some red Big Wool. Why not make it black?

So now what I'm wondering is this: I've finished the back and half of one front for a basic drop shoulder cardi. Do I simply rip back the last few rows of the back to where the armholes should be, and continue knitting the front in pieces, and make a seamed Tomten? Or is that actually more work than ripping the whole thing out and starting over completely? Or should I just finish this cardi as I started it and make the Tomten in red as intended?

Why do I always cast on impulsively and then overthink things?