Hi Maddie,
What a great dress! I love it. With it I would pair black platform heels - though nothing as chunky as these wedges. A pair like the ones Dannii Minogue is wearing here (ignore the belly, you'll look totally different!)
They cover most of your feet so are like ankle boots, but with a maxi you need to show some skin otherwise things can look clumpy and heavy down the bottom. Your toes might freeze but it's all in the name of style I'm afraid. If you really don't care about freezing, then go for a pair that are slightly more bare like this:
But these might be a bit much for a movie night, even if it is SATC2.
Basically, a covered pair of heels in black and that flash some foot will be great with this dress. In summer of course, you can wear it with flats or heels.