I can confirm the Hubba Hubba and copper spur as good tents. Most MSR products are excellent; tents, stoves, snowshoes all superb. Big agnes is hit or miss in my opinion. Another good tent brand is Nemo.
For what you looking for (Winter camping in CO, maybe AK) I would highly recommend the REI Cirque ASL tent. This is a borderline four season tent with a weight on the heavy side of a summer tent at a cost far less than the true four season tents from MH, Marmot, Hill, and others.
For any late season to winter camping I would not recommend a tent with mesh sides unless said mesh can be zipped closed. The cirque offers the flexibility of mesh or solid side panels. I have used this tent in everything from sand storms in Moab (try a mesh walled tent in a sand storm, not fun) to climbing Mt. Rainier and everything in between including bow through 3rd season hunts in colorado. Tent is also well built for multiple guy line attachment points for anything but typhoon conditions.
Like others said, side entry tents are superior for two people unless you plan on digging in to the side of a snow covered mountain.
Lasty, tents can be cheap. Cheap tents will leak, probably sooner rather than later. Mid price tents from established backpacking brands will last you many many seasons. I have 200+ nights in a Hubba solo tent and it is still water proof.
And yeah, winter camping is cold. Fill up a nalgene with boiling water and throw it in your sleeping bag. Much lighter than a four season tent.
