What do I do with the viney growth on my dipladenia plant? Can I root it to start another plant?

Question

I brought the plant indoors for the winter months.

Answer 1

Yes you can easily propagate this plant from cuttings.
This link will help you, it is referencing the Mandevilla but the procedure is exactly the same for your plant.

https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-propagation.htm

https://www.gardeningknowhow.com/ornamental/vines/mandevilla/growing-a-dipladenia.htm