I would highly encourage you to go with down. True, it is a problem if it gets wet, but in 30 years of backpacking in the Rockies, New Mexico to Montana, and have experienced day after day of heavy rain for much of each day. YetI have never gotten my bag seriously wet.

But then I am super careful with it. I pack it in a water resistant light-weight nylon bag, but only after I have inserted a large turkey-roasting bag (available at most supermarkets) It weighs less than an ounce, is highly puncture & water resistant. I also use a pack cover for additional help.

Even if my tent condenses heavily or even leaks, my bag is kept dry because I'm on a TermaRest 3/4 length mattress, with my backpack for my legs & feet. This keeps me above any water on the floor. I use a light weight pack towel or pack spongue to mop up any water ring it out in my vestibule. If I ever replace my bag, I will probably get one with a gortex top for added protection.

Although down is more expensive to buy, it packs smaller than any synthetic, and it also will last much longer than any synthetic bag. In the long haul, you will probably spend less keeping yourself in bags. I replaced my first down bag after 25 years and averaging 15 - 20 nights a year. I still keep it for a great bag for warmer trips, usually car camping. Down also has a wide comfort range. I have use it from + 20 to in a friends living room at 75, opened up and laying over my like a blanket.