I'll be backpacking in the White Mountains, NH during the last week in July. Temperatures (as far as I can tell) straddle between 55 to 75 degrees. I've done a lot of backpacking, and always use a +20 bag in the summer, which I typically end up sleeping on top of. I'm looking for suggestions for lightweight sleeping gear---anything from sleeping sheets to liners. I'm a short, petite woman so any suggestions tailored for my frame is ideal. Thanks very much!