In pots is fine. In the garage is fine as long as temps do not go into the thirties. The house will be drier so you want to have no leaves and force dormancy by cutting off the leaves. You can leave them outside as temps get into the low fifties and move before colder conditions. Usually 50s start dormancy but some plamts can be stubborn.

So if temps don't go in to the 30s, I can leave outdoors? They will be under a patio cover, so they won't get soaking wet from the rain, if that's a concern.

most people start getting concerned when the temperatures get in the low 40s. Mine remain out all year and have had bouts with frosts. I have lost a few but most (talking hundreds) survive. So, in your case, you can leave them under your cover until temps in the low 40s are predicted and then consider more protection.

As a professional killer of plumerias. You don't want them outside when it's below 40.

Juicygirl- there are some habits that can reduce your damages. Fertilizing into fall encourages green growth which is very sensitive to cold. Stop fertilizing in late summer. Giving your plants high potassium (last number) in late summer or products like Protekt (0-0-3) help to harden and prepare plants for colder weather. Moving plants close to a south facing wall or under a cover or overhang helps them endure colder temps. Bill