they should be fine in the cold frame. Usually leave mine outside.
welcome to GoY too

I agree with what SBG has said, the cold frame should be covered over in very severe weather, if you live in the north as SBG does.

Imo the hydrangea and buddleia will be OK. The fuchsias ,even if they are theoretically hardy varieties may well not survive the winter.

Contrary to other opinions on here I'm not convinced leaving fuchsia cuttings in a cold frame over winter is a good idea.I grow hundreds of hardy fuchsias a year but bring them in over winter and keep them on a windowsill in an unheated room. I have tried leaving them in a coldframe but had significant losses. I have no losses bringing them indoors.

If the fuchsias you are growing are not of the hardy variety then I'd very much doubt they'll survive in a unheated coldframe

I've also lost all my fuschias during the winter in the past, even though they were also in a protected cold frame, so wouldn't chance it again! Annie