Growth buds on rhododendrons form in the leaf axils (where leaf joins stem). If you make a cut just above a rosette of leaves, new growth will emerge from the dormant eyes there. If cutting into a branch below any leaf rosettes, look for faint rings on the bark which mark the ends of previous growth periods where there once were leaves. Careful inspection should reveal small bumps which are growth buds under the bark. Make your cuts just about the rings and dormant buds below them should be stimulated into growth. If you can't find any rings or dormant buds on bare branches, make your cuts where you must, after, when new growth starts, remove stubs down to new growth. Azaleas however, have dormant growth buds all along the stems just under the bark...

You can just keep them in water over the winter or put them in a pot and keep them protected then plant them in the garden in the spring. Unrooted brug cuttings can't be left out for months at a time like plumeria cuttings or they'll dehydrate and die. I wouldn't chance their developing a good enough root system this late in the year to leave them out, especially if we have a colder then average winter like last year. I also wouldn't allow the newly rooted cuttings to go dormant. Keep them growing but you can let the new potted brugs go dormant like we discussed.

Where do you live and what kind of hydrangeas are they? Different types of hydrangeas will sustain different pruning practices, depending on how they bloom (old or new wood, occasionally both). In milder climates - like mine - buds on viable wood are already present but it may take longer for them to be very noticeable in colder areas. To be on the safe side so as not to entirely remove any flowering potential for this season, you can always wait a while before removing stems that no longer show any life to confirm they are in fact dead. We could be even more specific if we knew what type of hydrangeas you are referring to, though.

Do Brugs survive in the ground in DFW? I had mine in pots and pulled them in the garage. They were blooming and had lots of buds that have now bloomed and the garage smells amazing. This is the first year I have grown them and I am still figuring out what to do with them over winter. Lots of smaller potted plants have come indoors but I don't have room for these in the house.