Protecting pots from cold in winter?

OK, so permaculture in pots, the first thing that comes to mind with plants in pots not in the ground is how to keep them alive through the winter. I always loose several plants in pots that way. I usually use mulch or leaves from fall, but still have looses. How do you cope with the heat loss through pots in winter? Thanks.

Expanding on this question: all of the methods I know of for giving the pots thermal protection (putting them on the ground or in sheltered corners or against walls, covering them with mulch, shoveling insulating snow over them, wrapping, covering, et cetera) come at the cost of increasing the opportunity for nibblers and burrowers to devastate the contents of the pots. I'd be very interested in ways to protect pots from thermal damage that don't offer access and cover and concealment and habitat to small animals.

Well, I bring indoors any pots that I think won't make it outside. In winter my windowsills are full. But I don't have huge numbers of pots nor huge sizes, so that might not work for you.

Partly, I cheat, and live in an area where it rarely gets properly cold. (I live in London, UK, which is a heat island of itself, as well as the southern UK being pretty temperate anyway). I don't think we've had below-zero temps this year (I've only seen a frost maybe twice) and we probably won't now. That's becoming more usual, which is another post altogether, but even 30 years ago when I was small, and lived a bit further out in the suburbs, -5 deg C was rare and considered Really Very Chilly Indeed. Those of you who live in places where it gets actually cold can now laugh at me

I also avoid growing things that need much tender care, because I am a very lazy permaculturist. So my current approach is to leave everything as-is and hope it survives. I have such a small garden (and I am really so very lazy) that for me this is a reasonable way to find out what is the best fit for my conditions.

Having said all of that: I have in the past had plants I was more worried about and which did need protection. I've used bubble wrap (around the pot, around the trunk of the plant if it's the sort of plant that has a trunk, and over the soil; make sure there's a bit of a gap right around the base of the trunk to avoid it getting damp and rotting). I also use the thermal mass of the house -- more delicate plants go right next to the house against the south-facing wall.

I heard, on the radio show Gardener's Question Time some years ago, in a discussion about satsumas, that the real risk isn't *cold* so much as it is *cold and wet* -- that it's the water that's more of a problem. They suggested keeping pots dry over winter. I'm not sure how well this advice stretches to plants that aren't satsumas, but it might work for anything that expects to hibernate over the winter?

Can't offhand think of any solutions to mulching without also creating cover for nibbling beasties :/ though just insulating the pot might help and wouldn't provide much cover?