Defence 6

Synthetics (like the Defense 6) are great for the wet, brutal cold imo. Even with the bivy cover, you WILL get condensation from breathing or just from the outside air, and synthetic still keeps you a little warmer if it gets damp. The pack size and weight are rough, though. You’ll save some space and grams ditching the extra liner if you can swing a warmer main bag.

Carinthia Defence 6. Bulky, rather cheap for the temperature range you end up buying, heavy, but also heavy duty!

Well you have very specific needs. First question. Are you even allowed to bring your own gear? The defense 6 is a really good option. Carinthia supplies a lot of nordic countries with their military equipment. Of course the defense 6 is the private version of it. Can you not get a warmer or newer version from the army? Synthetic will be your only realistic option. Down is useless when wet. And in the harsh alaska conditions addionally to army stuff and not a relaxed holiday its just not realistic.

Carinthia Defense line. Goes to -30 degrees celcius (or more...) and won't break the budget.

Try Carinthia sleeping bags! They are the fuckin best but a bit expenaive

I like my Carinthia but was baffled that it does not have a baffle which to my mind makes it unsuitable for cold conditions.