@Philipwonel,
Mine is definitely a slow grower. Mine is in a large container (24" x 24" square terra cotta planter). My source has his in the ground in his yard. Or I should say, he
had his in the ground in his yard.
I have my planter set up on bricks, and I
can slide a furniture dolly under it and roll it into the basement. Some winters, I probably will be able to leave it out. Other times, I bring it in.
If (when) the forecast is for an extended time (3 days or more) with daytime
high temperatures below freezing, I bring it in, and I keep it in until a couple weeks before "average last frost" date. So far, with this plant, I've brought it in every year because since I've been back in Georgia, we've had at least one extended deep freeze period every winter. Before I moved to Florida for a few years, when I was living in Georgia before, I had one in a similar planter, and a few mild winters, I was able to leave it out all winter.
My source for this tree died off completely last winter. That's whey I definitely need to layer off at least one more plant to return to my source. I also lost my outdoor, in the ground sage, rosemary and even my thyme and some of my oregano last winter.