4 Season tent suggestions?

My son lives in Denver and tents a lot in 3 seasons. Not usually long distances from the TH or vehicle. He has a Big Agnes Copper Spur - UL3. For 2 people usually.

A few questions;
Would you take this tent out in the winter?
What 4 season tent would you suggest he purchase? (He is still paying off student loans and is not in a high salary position)
If buying a 4 season tent, do you still recommend a 3 person tent for 2 people? This is what we have done for summer tents. Or do you just get a 2 person 4 season tent so that there is less room and able to retain more body heat?
Is condensation an issue?
What make a 4 season tent more suitable for winter use? Just stronger poles and no mesh ? Heavier material?
Thanks for any help for the newbies!
Clayton

Some of your answers might be here.
https://onyourownadventures.com/hunttalk/showthread.php?280998-3-season-tent-vs-4-season

Generally, standard 4 season tents are quite heavy, at least everything I've looked at. For a hunting season and winter tent look into a floorless pyramid or teepee. Seek Outside makes really nice stuff. The Cimarron would be about right for two. With a stove jack and the carbon fiber pole I think they are around $450 if my memory is correct and really light. Then down the road you can add the stove. They are singe wall so you have to manage condensation, the stove helps with that too. I would agree with everything in that other thread as well.