Ok so I must be the odd one here. I have a HH explorer D. With my DIY underquilt and a cheap 20 degree bag I sleep just fine down to at least 40 (it hasn't gotten colder to try it out lower.) My bag is a left zip mummy bag, that is a huge improvement over the first bag I tried which was a right zip and a rectangular one. Too much bag, zipper on the wrong side. I place it in the hammock in a diagonal position and then sit down on it, pivot my feet in place, squirm a bit and then pull and tug the sides a bit and zip up. It took me 4 or 5 nights towork out the moving around thing, but a bag works fine for me. It wasn't intuitive the first time but experience helps. Even getting out to relieve myself is coming quicker with practice.
Roads go ever ever on, under cloud and under star; Yet feet that wandering have gone, turn at last to home afar. Bilbo Baggins