Heucheras are pretty hardy. However, those are quite small and are in pots which would freeze easily. I'd be inclined to keep them indoors.

Remove their pots and plant them out, even a temporary spot is fine but let them develop outdoors or they'll not harden up.
Mulch or fleece them over the winter if you're worried.

You sure, Louise!? Those are pretty small plants where I live in west of Scotland, I'd be a bit wary of planting them out now with the rumour of winter weather expected by mid-October?

You're right about the difference in temperatures between north and south and if it was you asking i'd say give them protection but where Containerchris is i'd risk it - it would be nice if he/she posted again to comment.

Hi Louise, I only got into gardedning this year and know next to nothing.
I have worked very hard to make a garden of sorts, but due to being part disabled I find it better to use containers and pots for my plants.

I have quite a collection of good sized Heuchera's which I will mulch and move to a sheltered spot.

I was not sure about the young plants I asked about, my gut feeling was that they were a bit young to survive outside over winter.

Rightly or not I will put them in an unheated conservatory over the winter, that way at least I have tried to protect them.

Only time will tell, fingers crossed, roll on next spring.