Originally Posted by
Bacciagalupe
Don't let your sleeping bag get wet. Problem Solved.

Agreed. I also use a down sleeping bag. I bought it 36 years ago and it's been used on several trips per year. It has never gotten wet except when being washed. If I ever did get it wet on a bike tour I think I'd just keep riding to the nearest laundromat. But keeping it in a waterproof bag inside waterproof panniers has worked so far.