Camping advice

[ZenGum]

Last weekend I did some hiking and camping (sorry, no pics, I find taking photos gets in the way of having experiences). It being winter down here, nights got pretty cold. I am not sure I managed the tent as well as I could have. I think quite a few folks here have cold weather camping experience, so I thought I'd raise the question.

The conditions were down to 2 to 4 degrees centigrade, but dry, with mild wind. I was snugged up inside warm clothing and a sleeping bag inside a tent. The tent is a two-piece; a waterproof base with a cotton wall/roof structure, and a waterproof fly over the top. The fly has covered vents for ventilation, but I kept these closed with the idea of keeping the warm air in. It seemed to work at least until the wee small hours.

In the morning, the cotton innerwall was dripping wet. It could only have been condensation from my breath. And when a breeze blew, the water would evaporate and this would chill the air further.

So I am wondering, would I have been better off to allow some ventilation to clear my humid breath, and tolerate the constant draft? Or is it better to eliminate drafts as much as possible?

Any of you highly trained military commando / mountain hiker / Scottish Highlander types got any advice?