@chai2,
Cold weather clothing isn't necessarily restrictive. There are some great new fibres out there that are light-weight but extraordinarily comfortable - and silk is still the best in cold weather (in the right knit).
I need to be fairly cool/cold to sleep at all. I used to work at a company where the president thought the boardroom should be kept cold to keep people awake - others were freezing while I was so comfy I had trouble staying awake.