The original tarp tent (ala Henry Shires) was not a 4 season tent. To be four season, it would need stronger supports to help it hold against high winds and snow loads. Look at Henry's four season tarp tent, the Scarp -- the extra poles and extra guy out points plus double wall construction would be a good clue as to how much extra you'll need to put into the construction.
The other sort of tent that seems to do well in snow and wind are the teepee style tents, like the 'mids from Black Diamond. I'd guess those would be fairly straightforward to replicate.
"In the beginner's mind there are many possibilities. In the expert's mind there are few." Shunryu Suzukihttp://hikeandbackpack.com