So why not add a waterproof bivy to a hammock? On my trip in the Sierras, a simple water resistant hammock bivy would have surely enabled me to stay the night in the hammock. But what if I had to hole up the next day? In those winds that topped 100 mph, a mountaineering tent with a vestibule suitable for cooking would have been very helpful for melting snow into drinking water. Creating a tarptent large enough to hang a hammock inside is one solution, but even this has disadvantages. First, the profile necessary to provide adequate coverage is quite large, and the boxy shape does not spill wind as efficiently as geodesic mountaineering tents. This can lead to shelter failure in high winds an inconvenience in many conditions, but a possible disaster in four season hammocking. Second, mountaineering tents generally have a separate vestibule so that cooking does not create condensation inside the primary living space. A hammock tarptent for four season camping would have to accommodate for these issues. Still, the hammock tarptent would provide an adequate solution for a range of cold and windy conditions.
I have done a fair amount of reading and find that allot of four season hammocks (I am a little over 6' and 200lbs) are fairly close to my weight as a max weight rating.
And then this one that was of course mentioned in the thread mentioned above. However is not a dedicated four season hammock, this one either comes in three season or winter.