Cold Zero:
"Lightweight" and "4-season" are not very compatible.
A couple of Hilleberg tents are real good but as mentioned, very pricey.
What I use is a Kuiu Storm Star 2 person tent, which costs $600 and weighs about 5 1/2#. It's a rare tent that is actually a 4-season tent but has only three poles. I've used mine in some pretty good blows.
Kuiu Storm Star 2P I have learned to be skeptical of off-brand manufacturers that claim their tents are "4-season" just because they have a full-coverage rain fly, but actuall only have 2 poles.