It really depends on your style, and what type of "camp" you want to have, is it back country, are into minimalist style, living out of your vehicle?
For me I'm going low impact, low prep. I have a diamond combat II, its lightweight stupid easy for setup, and 4 season. I generally dont worry about keeping the tent warm, I lean towards a better sleeping system, but again I like minimalist setups. You can do your own 3-4 layer sleep system that can keep you more than comfortable even on the stupid cold nights, use a sleeping bag liner with a light weight mummy bag, then any average xl mummy bag, and the heavy down or canvas fleece outer bag. You could look into a gortex bivy cover as well itll stop any condensation from soaking into the bags. I have used the little red buddy heater, but I found it to be too hot in this tent, so I'll generally only use it in the am, I'll just start it up as soon as I wake up, before I get out of the bag to get dressed. Another thing that is a god send is a good sleeping mat, even if you gonna be on a cot, it insulates you from ground temps when your body is compressing the bags. I dont have any pics of my setup in action, but if I get some time I'll snap some of it setup this weekend...