Anything like that is more for -10C. To give you a reference I used UA 2.0 base/ a thinner (but 900 fill down montbell down sweater)/ and Hover 3l for opening day on Sunshine.
For what is worth I highly recommend something like Eddie Bauer First Ascent/Patagonia down sweater/Montbell ex light over the ak mid layers. Same price but lighter and has real 700-900 goose down fill vs the 550 fill ak has.
“I train every day of my life as they have never trained a day in theirs.” – Alexander Karelin