I've also bought some bakers fondant which intend to add on top of the BS frames, come October.
Skydragon,
They should have enough stores by then to keep them going the whole winter and into the spring (brooding ready for the early honey flow). If not, you should be feeding concentrated sugar solution before then to help them to do that.
Fondant is generally a means of feeding bees in the new year when stores are running low for some reason.
I had bees foraging right up until Christmas last year, so a lot depends on location and weather. I am in South Lincs. and had not seen bees taking in pollen on the winter solstice before. This year could be different, but we will have to wait to find out.
If the weather carries on like this I wonder if they will survive
No reason why they should not if you keep feeding them now, so they can build up numbers initially, and then fill them up with winter stores. And keep that fondant ready if they run low during the winter.....
Regards, RAB