I've done both a 26 day backpack trip and a 23 day river trip in the Grand Canyon with down bags. If you sleep in a tent, under a tarp, or under a rock overhang it's no problem at all as long as you have a very reliable (Watershed) drybag. I usually wrap my sleeping bag in a trash compactor bag inside a Watershed, which is excessive since I've never had a Watershed leak, but I don't wanna sleep wet.

If you plan to sleep out under the stars, you just need to let the bag sit in the sun for a few minutes in the morning to dry all the way before you stuff it. Most nights, dew is minimal out there and things dry really quickly. Many nights there's no dew and you can stuff it immediately.

I've owned two brands of down bags and loved them both. The first was a Marmot that I got used in the late 80's and used probably an average of 100 nights/year for about 12 years before it died. Got a Feathered Friends in 2000 that I've been using ever since and it's still going strong.

Down is so much more comfortable, lighter, and stuffs so much smaller that there is no contest on which to get as long as you are careful to keep it dry.

Have fun in the ditch!

Leland