From reading about what the carp fishing guys use for their overnight sessions, the
genuine British Army sleeping bags are the business, this was compared to other commercial ones.
Plus they can be had for peanuts on Ebay.
There's a 4 seasons version.
http://www.ebay.co.uk/sch/i.html?_tr...g+bag&_sacat=0
What these nutters don't know about camping out in middle of winter isn't worth knowing about