Depends on what your Wintering plan is.

If you have room by a S, E, or W window, don't cut it at all if it is under 5 feet tall, just bring it in as is.

If it is too wide then cut off the lateral branches at the main trunks and leave on the two vertical ones. The root those long branches you cut off.

Wildcat

MGT, if this was my plant I would go with the 'Y' stalk in the middle of the last photo and remove the stalks that go out from it. You then will have some large cuttings in which to start rooting and will bloom just like the main trunk next year. It would then become more of a tree shape and not a shrub that you have here for the second year if you keep it trimmed upward. I'm sorry to disagree with Wildcat but if you want them to really preform, resting in the winter months up north is a must. Think of it as a human that is on the go all the time without resting it will wear down fast and not preform at it's best if it doesn't rest some. You also have to ask yourself if you want the shrub shape or more of a tree form? Both if given the right conditions can have flushes of well over 100 blooms.

I agree with karmahappytoes about the rest period. Last winter I let several cuttings go into bloom, but this summer those cuttings did not do particularly well. Those that had rested did much better.

I would add that 8-9 degrees Celsius is not too cold. In fact, Brugs love cooler temperatures. I would wait until frost.

Jérôme