My two plumerias are all grown in a container. Since my area gets windy, I have to use heavy containers otherwise it so easy to topple it. One thing to make sure, it must have drain holes, whatever material it is made of, always use one with drain holes so excess water and salts gets flushed away.
When they were still younger I can still move them in and out of the house when the winter season arrives. Pretty much they go dormant anyways once temps starts falling below 50F and light levels becoming weaker.
I use cacti soil and I add a lot of pumice to the media, like 50% pumice, since the past couple of years I have kept them outdoors year round and during winter time, we get rains here, so have to make sure the media stays very well draining. I used to try to cover it with burlap, but I find just let the plant feel the air around, and allow faster dry out time. Provided our outdoor temps during winter does not go below 30F, then the plant endures well. It also depends actually what Plumeria variety you have. Mine is a Celadine so it has higher cold tolerance. But if we do have a forecast at the 20F level, that is a dicey situation, I may try to cover it with burlap but it really is too tough for Plumies and for any other succulent I have. At those temps I can already expect extensive cold damage.
During the long, hot and dry period here, if the Plumeria is already awake, leafing out nicely, then I can water it everyday. It is actually quite water thirsty. And we do hit now a daily 100F and higher outdoor dry temps, so got to keep the plant well hydrated. It is after all a tropical succulent and thrives nicely on humid conditions. My area does not get rain for 6 to 7 months, so compared to other areas, I have to compensate for the excessive moisture loss this plant will suffer.
For most of my succulents and other sensitive plants, once outdoor overnight temps starts hitting 50F and below, then I have to start moving them back indoors, so they can acclimate slowly again. At times, some succulents, like Plumerias, they just go dormant anyways during the cold period. Got to wait again in Spring when overnight temps starts going 50F and higher before I attempt to bring them out. So less to no watering while indoors, just letting them rest safely.
The only plant I can put in my unheated garage is a Clivia. All the rest are overwintered in a room with either southfacing or west facing windows.
