I spray my cuttings practically every day, at least when the temperature gets above 90F in the greenhouse.
James, Scott Pratt's stems and branches are really thin when they are young (compared to most plumeria varieties). It can be a challenge keeping them hydrated when they are cut and often when they are first rooted. If that plant (or any other) doesn't make it, please let me know. I can easily replace it/them in the spring.
I don't store my newly-rooted cuttings or seedlings in bags. I keep them potted and keep them lightly watered through the fall/winter months. They will either be in the garage greenhouse or in one of the permanent greenhouses. They won't go completely dormant, losing only some of the older, larger leaves during that time. They should continue growing, though more slowly than in the spring and summer months.