One sleeping bag or two?

[burger]

I'm doing a flip-flop in '06, starting NOBO from somewhere in Virginia around May 20th. I'm wondering if I should stick with one sleeping bag for the whole trip or start with a summer-weight bag and switch to a warmer bag around Hanover. Because I have allergies, I have to use a synthetic sleeping bag, so the weight difference between a 45-degree bag and a 20-ish-degree bag may be considerable. Will a 45-degree bag be warm enough to get me through the summer months, or should I just take a 25-degree bag the whole way?

[Blue Jay]

Much of your decision depends on how hot you sleep. I use a combination of a 20 degree bag, silk liner and fleece bag. In summer I carry the fleece bag and silk liner and often only use the liner. In the winter or the Whites I carry all three. I sleep hot so all three take me to 10 below. There are 45 degree bags that weigh less than a fleece liner. If you can afford that go with it. Again much depends on your comfort level. I know people who have to have a 10 in the winter even in the south and others who use just a 20 alone even in the Whites.

[chris]

Blue Jay's comments are spot-on: It depends. In my decrepit old age I get cold easily. I'd bring the 40 degree bag until it got chilly and then change to a 20 degree bag. One option that people use a lot is the fleece liner in the summer thing. I wouldn't do it because my 40 degree bag weighs less than most fleece liners. But, the liner is cheaper.