I have just finished the JMT using my Hennessy with a nest Underquilt and WM 20 degree bag. Two nights the temperatures fell to somewhere around 20 degrees and I was too cold to sleep well.
I slept with a synthetic tee shirt followed by a fleece / synthetic ski undergarment followed by a Mont Bell down jacket followed on one night by a Precip jacket in a 20 degree Alpinlite bag, also wore a good insulating hat and wool socks. I awoke in the early hours and could not warm up enough to sleep, I was not cold enough to be in any hypothermia danger but not warm enough to fall back to sleep. The cold was coming from underneath. I did not have a stainless hot water bottle, I had given that to my sister who was suffering much worse than I.
I plan to start the AT in March and I wonder if I am going to need to get colder weather gear to have comfortable nights.
Do you think it will be advisable to get a winter nest and a 5 degree bag to sleep well, that's a lot of expense but I will spend it if I need it to enjoy my adventure of a lifetime. Is the winter nest likely to make the difference that I need?
Typically, if it's cold, I am warm soon after tucking in, I sleep for a few hours then awake cold. If the temperature is not too cold then just laying awake for a while warms me up enough to fall asleep again and repeat the cycle. The two days around 20 degrees I did not warm enough.
I do eat prior to turning in to activate my metabolism but I am afraid that at my age my metabolism slows rather dramatically when I fall asleep.
Any advice? Do I just need to grin and bear it when the temperature fall into the 20's