I'd pot them up while the weather's still dodgy and plant them out in the spring.

I agree.....Daylilies are very hardy. Not usually ones that you need to lift in the fall although if you had them in pots then it was probably wise. If they were in the ground you can just leave them.

Would it not be better to leave them in the pots in future and give them shelter if necessary? I've never had any problem with hardiness of daylillies, but that may be just that the varieties I have are fully hardy?? Anyway, welcome to Goy Grandad:-)))