I also unpicked the collar. Then I sewed up the new side seams and threw in a few haphazard darts. I re-attached the (now shortened) sleeves, and in the highlight of the entire project, learned how to use the rolled hem attachment on my sewing machine to finish the sleeve edges before attaching some lace trim (also thrifted).
The fit ended up being too wonky for me to be thrilled with the outcome, but I like it enough to wear it frequently-- even 5 months later.
(many thanks to my four year old photographer)
Time: Way longer than it should have-- I worked here and there over the course of