Digging up your plumeria then often bagging them helps with winter storage issues where space is an issue. If you can keep your plumeria growing and out of dormancy or have a variety as I do that simply wont always go dormant below 50°, more power to you.
Many plumeria growers especially where the summer climate permits amazing plumeria growth, even if winter temps drop below 50°F have many, many trees and much, much larger than your 1-1/2 foot cutting and so winter storage can be a problem. We live where growing conditions are prime for plumeria and we take full advantage of it to have beautiful flowering trees.. My tallest tree out grew my heated 12ft tall greenhouse in 2015. I protected it in the garage in 2016 and 2017. It wont fit in the garage in fall of 2018. It's already grown 8" so far this summer. I have little choice but to uproot it, or trim it back, which I dont want to do.
I hope this answers your question
@fwmosher. Do your plumeria ever get to full tree height in your short growing season?
