One of my great weaknesses in gardening, is trying to keep "one of everything", which includes many plants that are not hardy in the Seattle area. This includes several Brugmansias. They have gotten big enough over the years that it is chore for me to bring in the pots to the greenhouse, not to mention the amount of precious space they take up. So, time for an experiment.
After bloom season was done, I top the canes down to about 12" (bringing some insurance cuttings inside, just in case). Then, grabbed one of those "wall o waters" used to protect tomatoes planted early in the season. I used a watering can to fill the tubes to ensure there was not too much moisture added to the pot. Since the pot was smaller in diameter than the wall o water, a binder clip was used to keep it in place. I gathered up some dry leaves and then filled the empty space for extra insulation. The pot was then placed the pot in a south facing location, under the eaves against the house.
On cold sunny days, the water is warmed, which slowly releases overnight. I leave it there until about May/June. So far this has worked for me 2 years in a row, last year we had a good week with lows in the teens, the brug sailed thru with no problems!
Now I have a little forest of Brugs on my patio from the rooted cuttings as well! Such heavenly scent on warm summer evenings. I'd almost swore off of them due to spider mite issues, but I've found that 100% neem oil mixed at .5 to 1.0% with some dish soap is working wonders!