Yes, I would alter the pattern. If there is extra fabric with no place to go, it’ll stick out. If the rest of the bodice fits ok and it’s just at the top, it could mean that you have narrow shoulders.

that’s also an idea. Make sure you’re choosing a size based on the bustline and then making adjustments to the waist if necessary. The bustline in the pattern determines the shoulder of the bodice. This will only be an issue if you have a large bustline but small, narrow shoulders.

does the dress utilize a facing and that’s what has the interfacing on it or is it fully lined? Yes, I think a dart could help but, for this dress, it would require undoing the neckline seam and having a friend help you out. This way they can pinch the excess area, pin, and help you establish how big to make the dart. To make a dart, you’re essentially looking for the greatest width, so how much is being pinch at the neckline. And then the length of the dart, or how far down your back is the material sticking out. You would then, on the dress, mark the edges of your dart width, at the top, then find the center between these two marks and draw your dart length. Then use a ruler to connect the edges of the dart width with the bottom of the dart length. Now you know where to sew your dart. If the dress has a lining, I could do each the main fabric and lining fabric separately when sewing the dart rather than try to do them both together. I wouldn’t worry about the interfacing, as I don’t think it’ll affect it too much with a dart but if there’s a facing, you might have to make it smaller. Another option, maybe go to a dry cleaners that does alterations and maybe throw the alterations a few bucks to help you pinch and pin the dart, if you don’t have a friend you trust to be accurate with this type of thing. Once you get it figured out, then you know what type of alteration will work for you and you can add these darts to your future patterns. good luck!