Oh, forgot to add that the "too tight" is not just an issue of cutting off circulation but tight clothing often is too restrictive. You will feel like a stuffed teddy bear and moving will not be fun. You also may need camp shoes - I have used felt mucklucks and also the old "Micky Mouse" boots. Down socks for sleeping are also nice. Do not forget proper sunglasses - they need side shields and need to be really dark. I use glacier goggles. I suppose ski goggles may work too. You did not say if you will be snow shoeing, skiing or walking? If you plan on falling down in snow a lot (the way I ski) bibs are really nice.