I don't think I would size up in this one. It'd be interesting to see, just for analyzing and all of that, but I suspect that this is just the right size for you.
As a pear you are two different sizes on your top and your bottom. Normally you want to fit for your widest part. Your hips are your widest part, and this dress is fitting them just fine! While also fitting your top half quite perfectly (that is a little difficult to tell with your arms up for the photo, but from what I can see, I would not want to go any larger.)
Compare to the dresses on your other thread. In those cases, the bottoms did not fit you nearly as well. They were a smidge too small in the hips. Can you see it?
Ignore hem length when you look for fit; hem length is the simplest and less expensive alteration. Focus on width. Does it fit in the shoulders? The waist? The hips? With this dress I say YES YES YES.
Hem length I think is a matter of preference here. I personally prefer lengths that hit at the knee and think this dress would look great at that length. But, midi's are in. So, you could certainly wear this as a midi. If so, I would be interested to see it with heels. But, would you wear it with heels? If you want to stay at midi length, you might have it tapered in just a bit at the sides. I would recommend pinning it and taking more photos. Pin it at knee length. Then try midi length with it tapered gently just a bit.