It does definitely depend on individual metabolism, hydration, caloric intake, etc.
Most people I've met SIGNFICANTLY overdress for cold weather while on the move, and underdress for inactivity at camp.
On the move anywhere from 10-ish to 40-ish, a 150 g/m2 merino zip neck and a windbreaker or hard shell. If temps could be hovering around freezing, you definitely want to keep the hard shell! Wet at freezing is a bad combo. (Paramo-like garments can work then, too, but want to make sure you don't get too warm.)
If it's really hard for you to start out in just those layers, toss on a thin vest (like a powerstretch or wool/Ibex vest). You'll probably ditch the vest by the time you hit your first mile, assuming you're hiking and not dawdling. Lower half, a stretch-woven pant is pretty ideal, probably not leggings while on the move, but perhaps a thin merino layer if you're always cold.
A thin stocking hat is great, perhaps with a thin neck gaiter, or just a thin-ish balaclava. Even the thinnest wool ones seem to come off a little into a hike, but usually finds its way back on when the ears start feeling a bit too cool.
I do recommend a VBL sock, active or sedentary. Over the years I found that my boots/boot insulation and socks would get soaked while on the move… not a good way to keep your feet warm and toasty when the mercury drops at night.
Best way of minimizing sweat build up is to wear less. Far better to be a little cool when you're on the move.
My preferred midlayer is a 300-ish weight merino wool hoody. Icebreaker, Patagonia, & Ibex all make some version. It's frequently the single heaviest item in my 3-season pack, but also my favorite layering piece.
I would bring shell pants for camp duty. In camp, toss on down pants or (notice the trend here) heavier wool leggings and pull the shells over. Can be lots of sitting and kneeling in snow, want to keep that insulation dry.
Down jacket for camp, absolutely. But don't wear it while hiking! You'll sweat it right out. Really big poofy for night. The more down the better, IMO… I prefer jackets with ~8 oz or more of down for cold weather with some prolonged sedentary periods like that. Feathered Friends and Nunatak make some nice stuff.
Gloves, again people almost always overdo the gloves. You'll probably be a sweat factory while hiking; I can rarely wear gloves while on the trail. 30-ish and rain is a good time to bust out WPB shell mitts though. A light pair of wool gloves (the BPL possum downs are nice, too) close at hand for a bit of nip; big poofy liners for the shell mitts. I think I've been using OR Cornice mitts for that last couple seasons, though I honestly can't recall if that's what they are. Something thin is good for around camp, and I always bring more handwear than I should need. They'll get wet, and you'll want at least one spare pair to have drying in your jacket. I like thin wools (preferably not too fuzzy) for camp chores like cooking.
Down booties or something for camp far, far superior to just a thick pair of ragg wool socks. My favorite camp footwear lately has been a pair of GTX overboots stuffed w/wool felt-pacs. I think Steger makes some mukluks that could also work well, ideas such as those.