I have substantial experience with "tarpish" shelters in the snow. I have both a BD(actually mine is a Chouinard - it's that old) pyramid and an MSR Twin Peaks (modified with snow flaps). I also have a homemade floorless dome that I have used on many snow camping trips.
My take is that these types of shelters have a place for spring snow camping - where there is plenty of snow on the ground - generally pretty settled, consolidated snow - and the storms are fewer and less fierce. That's the time of year I prefer these days for my backcountry ski trips, and the Twin Peaks is my shelter of the moment for those trips.
But for what I call "Real Winter" - big storms, deep fluffy snow, long nights and all - I wouldn't go with one of those, Id take what I call a "Real Tent". Real Tents, to me, include both double-wall tents with a nice big vestibule or two, and single-wall tents that are waterproof/breatheable fabric (Bibler Todd-tex, ID Tegraltex, eVent if you are lucky enough to find one). I'd want a vestibule with the single-walls as well.
With my tarpish shelters, being able to seal out the wind is dependent on being able to pile snow on the flaps around the bottom. This works great in consolidated spring snow - not so hot in a couple of feet of new fluff. And you don't have the kind of two-stage entry you can get with a vestibule (assuming it's big enough) where you can come from the outside into the vestibule while the tent is still sealed up, close up the vestibule, brush the worst of the snow off yourself, and then get into the tent. This keeps a lot of snow out of the tent that you'd otherwise bring in with you - and that snow will melt and get your gear wet.
About making your own - I wouldn't, not a winter tent. And that comes from someone who has made tents, several over the years. It's lots of work, and the likelihood of your equalling the tents you can buy is just about nil (no offense meant, I'd say that to anyone who isn't planning to make several versions of their design in order to work out the bugs). Better to find one used if funds are short, or scrounge some extra work in order to pay for it.
Just my opinion.