What kind of clothes do you typically wear when active in those conditions? Wear that.
If you have no experience in those conditions, you're going to learn some tough lessons that are hard to convey via text.
For starters, state what gear you have. In general, you'll want a warm hat, sunglasses, a buff, multiple layers on your upper body, a wind/waterproof layer, a puffy insulation layer, thin & thick gloves, long underwear, water resistant/proof pants with knee pads, warm socks, waterproof (and maybe insulated) boots, gaiters, and a sitting pad. Crampons or microspikes will be invaluable if it's a freeze/thaw cycle and there is mud or ice.
If you're hiking in and out every day, you can pack whatever you want in the truck and add/cull to your gear as needed. A boot dryer at the truck or hotel is a good call too, nothing sucks like cold wet boot.