Anyway, back to Snugpak. It's based in the United Kingdom, as you mention, and makes a wide range of outdoor gear (www.snugpak.com). Nothing too unusual about the shells on their sleeping bagsPertex is a superb material (I use it in the singular sense, but the "it" comes in several iterations). It's very light, durable, and water resistant, even though it's made from nylon, which tends to soak up more moisture than polyester. Several U.S. makers use Pertex in their bag shells, including Marmot. For the fill, Snugpak uses a Swiss-made material consisting of strands of insulating material that has been given a different finish and is "crimped" in different ways. It's similar to some European-made bags I recall from the mid-1990s, and which are no longer available. Those bags worked wellthe stuff lofted nicely and seemed durable. I certainly like the idea, and am willing to opine that the Snugpak bags match or supercede anything made by U.S. makers.
Snugpak's warmest bag is the Softie 18 Antarctica, rated to minus 20 degrees Celsius (minus four Fahrenheit) or minus 50 (minus 58 Fahrenheit) in extreme cases. Which means you'll (probably) live, but you won't be warm. Weight is just under five pounds, which is good for a synthetic bag but not necessarily spectacular. The North Face's Polarguard-filled Tundra ($239; www.thenorthface.com), for instance, is rated to minus 20 degrees Fahrenheit and weighs four pounds, four ounces. Several Snugpak bags are much lighter, but of course also not as warm as the Softie 18, which costs 134 pounds Sterling, or about $220 U.S. I expect you can find a U.K. Web retailer who would sell you one, and then you can report back to us!