It is, I believe, a 1949 state law that required all aircraft that carry less than 15 people to have survival gear, including a firearm and ammo. But small aircraft can only carry so much weight, so I suspect that the required survival gear would be minimal.

Re the temps, I just checked Weather Underground for Bethel last April 22nd. High temp 41, low 35, zero precip. A twenty degree bag should work just fine there. Link ...