Outer layer question and new Sitka Jetstream fit?

[BilboBaggins]

I used to hunt a lot as a kid and I am getting back into whitetail hunting as an adult. Trying to get a clothing system set up so I don't freeze like I did in my younger years. I have a couple questions about layering and the Sitka Jetstream.

For long sits will a thin merino base layer + light wool sweater + wool shirt + FL Brooks Down Jacket + Sitka Jetstream be sufficient? Temps can get down to 10F with windchill. Going with heavy bibs for lower body so I'm not worried about that but I want to be able to shed layers as needed for my upper body. Planning on doing some long sits but also want to do some active hunting.

Does the new Jetstream design allow room for a down jacket to loft fully? The arms specifically look very slim.

 

[MT_Wyatt]

Gonna say no. Long sits require significant insulation. 5oz of down fill, min, depending on outside temps. I can't do it below freezing without 7-9 oz of down.

Brooks puffy is trimmer, and thinner so could layer "okay" but I would treat the jetstream like a heavy more weatherproof mid layer - puffy over. There's no moving in a down jacket.