I'd use one cutting per pot and grow them under the right conditions that encourage thick, sturdy, well-branched plants.

No patent issues. Transplant up when the root mass has filled the smaller container, but before it becomes congested. Let the plant grow at a normal rate, inspect the root mass periodically.

Hydrangea root so quickly I usually root right into one gallon pots, one per pot, provided you have the space. This eliminates potting up from a four inch pot and the resulting check in the growth

Sounds like one cutting per pot it is! I appreciate both of your input! I'm glad to hear they tend to root quickly!

Lindsay,

I would also take a couple of branches that are growing close to the soil and carefully put a brick or stone on the branch to keep it in contact with the soil. Make sure to have one or more leaf nodes in contact with the soil. Leave the rock - brick or other heavy object on the branch and by summer or fall, the branch will root where it is in contact with the soil. Some propagators nick the branch and apply some rooting hormone where the branch in in the soil. Cut the branch from the mother plant when the roots are several inches and pot them up. Or, you can cut the branch from the mother plant but leave it where it is and pot up in the fall or the following spring. It is possible that the branches will have bloomed along with the mother plant so cut off the bloom and some of the length of the cutting when you pot it. I have found that some old hydrangeas are difficult to propagate - not sure why - and this will be a back-up just in case your other cuttings do not make it.