They are still alive!
If you recall, I took these cuttings from my mother-in-law's "Endless Summer" hydrangea. I stripped four leaves off the bottom to leave me with two sets of leaf nodes, dipped the stems in powdered rooting hormone, and then planted them in little containers with potting soil. I watered them and tented them (I think I used some large cellophane treat sacks from Hobby Lobby and rubber bands). This created a little mini-greenhouse environment for each of them, and honestly I didn't water them the whole time they were tented. I can't remember how long it took them to grow roots--maybe around a month? They flourished under their little tents! I debated planting them outside last fall, but I worried they wouldn't have had enough time to develop a good enough root system to see them through the winter. Instead I kept them inside at a west-facing window and have watered them about once a week. I don't think they are getting quite the amount of sun they need (we have a large over-hang on the house, plus the reduced daylight hours of winter), but my mother-in-law assured me they are looking good for plants going through the winter inside. They even have some new growth!
I'm excited to plant them come spring, and you can bet I'll be starting the process again with new clippings (because can one have too many hydrangeas--I think not!). All my research (or in layman's terms "googling") recommends starting clippings at the beginning of the growing season so you can get them planted and established before fall/winter hits. If you are hydrangea lover like me, I just wanted to pass on that this little gardening experiment seems to be working! (And seeing as these bushes average $15-$20 you can save a bundle of money if you start them yourself!)