Trying to get my clothes ready for the SS Antarctica cruise Jan 5. I have waterproof single layer pants and also the puffy ski type pants which give extra warmth. Do I need the puffy ski style pants or will the Columbia storm surge waterproof pants be enough with warm underwear? Have silk long underwear and bought Merino wool long underwear. Trying to be conscious of what I am packing. Will the waterproof keep me warm enough or do I need the ski pants? Thanks for any comments and advice.