Can it be cut back and mulch heavy and kept outdoors?
Certified GKH Gardening Expert
This depends on where you are located. This is a tropical, so if it gets cold, then I would bring it in as it isn't likely to survive outdoors. Here is an article for more information: https://www.gardeningknowhow.com/ornamental/vines/mandevilla/winterizing-mandevillas.htm