Speaking from experience, moonflower vine tends to get rootbound in containers. Plus it needs a lot of water. For a similar looking flower, white morning glory does a little better in containers.

I have grown Moonflower plants in containers for many years. You must provide constant moisture for the plants to grow, they dry out very quickly. Also, they climb very high, I provide a trellis at least 12 feet tall for them to climb on. Keep them well watered, provide a good water soluble fertilizer and they will reward you with beautiful flowers toward the end of summer.

I grew some moonflowers in containers a year ago - out of 27 seeds only 2 bloomed...the others all wilted off. Perhaps something in the soil? Weirdly enough, they came up miniature! Flowers as small as the tip of my baby finger, but they had that beautiful smell. They didn't grow tall, but continued to flower and even set seed. I saved some of the seeds thinking I wouldn't mind growing miniature ones, but have lost them since. I'm trying again this year, and definitely, they must be started early indoors.

I just planted white moon flower with 2 types of morning glory in containers. the morning glories are a beautiful solid blue and a blue and white. I'll keep you updated, I think the morning glory will do well, not sure about the moon flower, this is my first experience with it.