Check out BoneFire Gear. The guy makes an incredible hammock with a sewn in under quilt, built in bug net, and it's light as hell.
I've used it to about 5 degrees with wind and snow and had no problems. I cut a body length piece of reflectix and put it between the double layers of the hammock, wore a super down top and bottom, fleece socks, and a down hood to bed. Thought I was going to freeze. Woke up to downgrade clothing because I was hot. JRB 0 degree top quilt.
I'd trust it anywhere. Contrary to what most people think, the hammock with a proper under quilt is quite efficient because you aren't compressing the fill underneath your body like you do in a sleeping bag on a ground pad. The loft remains and (surprise) heat rises. Get your tarp right to block the wind and you'll sleep just fine.
That said, I'm also in the market for a tipi and stove combo. I spent a long three weeks on Kodiak and if it hadn't been for the stove inside our Arctic Oven, I'm not sure we would have made it out alive.
I think you'll be just fine in the hammock, there's just something about a tent with a fire.
Most people will bash the hammock option because they haven't had any (or positive) experience with them. In truth, a properly hung hammock with a topquilt, underquilt, and decent tarp will keep you quite toasty and you may find you sleep better suspended. I do. You need a true 4 season hammock (I use a Clark NX-250) and have been fine in cold weather. It's a smaller space to heat than a tent...more like a bivy. I have back issues so when I wake up after a night sleeping on the ground I am groaning, stiff and still tired from half-sleep. I awake from a night in the hammock refreshed and ready to go. But those of who prefer hammocks are the exception to the rule. There is a significant learning curve to hammock camping.
That's my biggest advantage with the hammock (apart from the ability to hang it anywhere there are 2 trees, regardless of slope, rocks, roots, water, etc). I wake up ready to go every day. My back and knee pain is gone with a hammock.
I wonder if there's a way to hang a hammock IN a tipi with a stove. THAT might be the way to go!
Maybe I need to start tinkering with a ridge line to ground length tarp for my hammock with doors and a stove jack.
Another vote for hammock gear. It takes some time to figure out but it's way more comfortable for me. I too would love to see a winter tarp\tipi that would work for my hammock rig with a stove jack. hopefully one of the top end backcountry hunting gear suppliers will take up the cause. I have warbonnet gear and it's top notch. I've never done anything below the high 20's but with an appropriate underquilt and topquilt I am confident I could bivi in complete comfort.