I would expect roots maybe around 3 weeks or earlier but when cold temperatures arrive, you will have to protect them indoors (and I understand that is difficult) or you can put them pots&all in a hole outside & cover them with mulch or you can put the pots near the foundation and cover them with clay pots thru the winter.

Thank you for your response. Any suggestions on how frequently I should be watering them now? They are located in a shady area under and overhang, so I'm not sure they're getting much rain water. Thanks again.

If your rooting medium is somewhat moist, you should be ok with just misting the leaves every other day or so. I agree with Luis to keep them in pots and partially bury them with lots of mulch. Best of luck!

My hydrangea cuttings were doing very well; they have thin roots after about 8 weeks. But now on a couple of plants some of the leaves have curled, turned brown and are kind of "crispy".

I have them inside by a window. I've been cautious not to overwater.

What mistakes am I making and what do I do now?

Hard to tell if they went dormant or if they have had moisture problems. If the roots look ok, assume that they went dormant and keep providing moisture. Make sure that they are not drying out due to the lack of humidity inside homes during this time of the year (or by heat vents that throw hot air towards the cuttings).