Cutting back is quite a large subject, and I'm still learning. I lost quite a few cuttings last winter, because I'd cut parts that were just too 'young' and green, BUT I'm learning my lessons ... HAHA.
Yes, you can cut yours leaving about 1', take the top portion with the branching (flowering region) and keep THAT entire removed portion in a bucket of water for the winter (about 3-4" of water), changing it now and then to keep it fresh, and you'll be AMAZED at how many good roots will come from that trunk. You're liable to lose leaves, then grow leaves, then lose those, all winter long, so you shouldn't panic about that. The remaining plant in the pot can be kept indoors or in the garage, but since it's not in the ground, I wouldn't trust leaving it outside over the winter. Both the cutting in water and the remaining portion in the pot merely need to be kept from freezing, though rooting is promoted by indoor temps.
, you can
wait to do that cutting until perhaps January, around here. The top (cut) portion should produce good roots in the water after only a few weeks, anyway, so that's your call.
Once spring comes along again (and it WILL
) you can then decide whether or not the upper branches on the upper portion are then thick and long enough to cut off for rooting, too. Whichever parts of the plant are BELOW the branching will again need time to form branching again (called the "Y") in order to produce blooms, and all cuttings ABOVE the 'Y' will have a head's start the next season, is all.
Have I completely confused you, now ? hahaha.
I've read other URL's listed here, so I'll go ahead and link you to a SUPER resource for brug info....
I've been a member for several years now, and that has proven to be the BEST $10/yr that I've ever spent in my life ! hehe. 'Course I readily admit to being totally addicted
to brugs, and perhaps you're not.
Well, you can still peruse several informative avenues there, without being a member, and I certainly recommend exploring the Brug Galleries !! CAUTION: Those may cause you to become hopelessly addicted !
Now you can't say I didn't warn you !
The Growing and Propagation link has good ideas about pruning, etc. , too.
BTW, this year, we'll be taking 2 plummies out of their pots, rinsing off all of the soil, and simply keeping those from freezing ... my friends do that all of the time, and they come back great, in new soil, come spring !! Now, that's COOL !! Sure will be easier than hauling in those pots again this year !!
(sure wish that worked with brugs, but NO !!)