I planted some hydrangeas grown from cuttings out in fall and had them survive, but later voles ate the roots off and killed a couple, so I recommend my vole protection, putting lava rock in the bottom and sides of planting holes. You could either plant them out now or overwinter them to plant out next spring, depending on how big they are, and how well you think you can overwinter them in an unheated garage or whatever.

As a hydrangea addict, I recommend keeping them potted and protecting the pots from freezing over the winter, then planting them out in the spring. They'll be that much bigger and better able to thrive. If they've been in small pots, you might consider potting them up a size.

Depends on if they are or will mature (harden off) enough. Potting on now might result in fall root rush filling pot and making for bigger top growth next year. But then, planting out now could have same outcome -- and they would be established in ground before next summer, instead of being planted out just ahead of summer drought, when soil has been becoming cold and soggy all winter (fall is the best time to plant hardy stock, whenever possible).