The Thinsulate, if thick enough, will be the best, better than wool by far and not as compressible as down under a shell.
But yeah, down will be the warmest until it gets wet with sweat.
**The best way to reduce this problem is to buy a light down jacket with DWR (Durable Water Repellant) treated down like Down Tec or Dri Down. Amazing treatment that helps down absorb 30% less H2O than untreated down and dry 60% faster. Eddie Bauer and LL Bean sell light down jackets with DWR treatment.
My advice: Wear the Thinsulate and take the down in a day pack for safety and backup when you stop for lunch or on a stand.
Eric B.
P.S. I used to teach Winter Survival to Army ROTC cadets and have been a ski patroller for 16 years so I know a bit about layering.