These plants should fare best if you go ahead and plant, water in, then add a good layer or organic mulch (compost, shredded leaves, wood chips, pine needles ... not rocks/stone).

If you cannot get them in the ground, you can overwinter in the pots. To protect from temperature extremes and alternate freezing/thawing, set the pots in a trench for the winter, or surround with mulch for the winter months to stabilize temperature.

It will take a toll on these plants - and you - if you try to overwinter them indoors. Bringing them inside at night will only increase their stress due to the temperature fluctuations - they won't know whether to go dormant or not. They'll do better outside.