BPL’er Dave Chenault has a nice snow camping summary here.
Mike C! also has his useful winter gear list posted here
I don’t know where you are in NorCal, but my first snow-camping experience was with the Sierra Club Bay Area chapter.
As Dave says in his recap, sweat is you enemy in winter. It was hard to get used to the idea of starting a hike out feeling cold wearing only softshell pants, my BPL hoody and a houdini in temperatures around freezing, but I was happy not to have to stop to de-layer after 15 minutes of snow-shoeing. And you need to stop and delayer if you are sweating.
My steepest learning curve inre winter camping was keeping my hands and feet dry and, consequently, warm. I wet-out multiple pairs of gloves my first two trips before figuring out that while actively snowshoeing or digging,etc, I often didn’t need gloves at all and at most needed a thin baselayer type glove. The thin gloves also dry quickly, and you can bring several pairs to rotate for the weight of one pair of 300wt fleece ones that will take forever to dry out once wet. Waterproof gloves are nice but just like a a jacket, you get wet from the inside. I got a pair of MLD rain mitts to wear over my baselayer gloves when necessary. I also have a pair of BPL featherlite mitts with built in Vapor Barrier liners for really cold temps. I’ve found for stuff around camp that requires dexterity, like eating, I like a baselayer of something like the Mountain Hardwear Butter liners under a pair of my old pair of OR Index mitts with flip down thumbs and fingers.
I haven’t experimented with much with Vapor Barriers except for my feet, and for those I find them indispensable. A pair of plastic grocery bags with duct tape reinforced toes and heels over a think liner sock and whatever sock/shoe combo you choose to wear over it makes a world of difference in having dry, warm feet at the end of the night. My last winter’s footwear system was liner sock/VBL/lightweight merino hiking socks/Rocky goretex socks/trail runners. I’ve read good argument in favor of neoprene socks as well.
Down or synthetic booties with fresh dry socks are also really nice for around camp.
A mid style tent should be fine anyplace below tree-line. When I used a mid in the Sierra, we dug out a shallow trench and put the mid over that. Those with 4-season tents just stomped down a snow platform. Most people on my Sierra club trips brought 3 season tents and were okay, even with heavy snow (3″+ overnight) on the 2nd one) you just may have to wake up more often to shovel snow off the walls. Condensation will also be an issue in any single wall shelter. Snow caves are fun but a lot of work for only one night.
Proper ground insulation is another big thing. I stack two Ridgrests. One torso-length and another full length, so I have an R value of 5.2 under my top half and 2.6 under my legs. Other people need more or less R-value to feel comfortable. And you need a CCF to sit on as well. Sitting on snow is cold.
Also, this seems obvious, but stuff freezes overnight. Like wet clothes, shoes and water bottles. Buy an isulated cozy for your water bottle.