Q.Can I Grow Plumeria In Hilton Head, SC?
If so, should I grow in a pot or plant in ground? Winter Temps can get in low 30’s at night.

Certified GKH Gardening Expert
You can certainly grow one, but you will need to bring it inside for the winter in a container. They are very cold sensitive and only stay outside in USDA zones 10-12. Read everything you can on growing conditions for plumeria. They are considered easy to grow, but they are very easy to overwater. In the winter, once inside, they don't need any water till spring.
https://www.gardeningknowhow.com/ornamental/flowers/plumeria/growing-plumeria.htm