The half sweater

So I’ve been working on a sweater for my son for probably about 9 months now…. Off and on, I take regular hiatuses from it. He’s now one and I’m afraid even if I do manage to finish this thing soon, it’s going to be too small. So what does one do with a half sweater? I could use the panel I have already knitted in another project for him and hope that this one doesn’t fizzle out too…. Suggestions would be welcome, if anybody is reading this 🙂