50 below is cold, really freaking cold, REALLY cold. I've seen temps in the 40's below a bunch of times and the coldest I've been in is 57 below. It hurts to think at those temps.
Try stopping at the Kittery Outpost next time instead of BP or Bean. It's a really cool store. It's also a few minutes from some of the best mt biking in the entire area, Aggy or Mt A (Mt Agamenticus) an old ski area with miles and miles of top notch primitive singletrack riding and hiking that will leave you thoroughly satisfied with the time spent there.