Even being female I am on the farthest thinkable end of cold sleeping and I understand very well the frustration and deception when getting a nice piece of gear, everybody likes it and ... it is just not warm enough for me.
Considering all the variables food, warm head, no draft, warm mat, mileage of the day, is it the first day/night on the trail, bath/wash to late in the evening, humidity, micro-climate of the campsite etc. all that can make a huge difference in the comfort for the upcoming night - for me with the same sleeping bag comfort temperature varies up to 15° Celsius! I was shivering in a 15°F/-9°C rated bag when the night was +9°C, and I slept - at least for a few hours - in the same bag at -15°C - that makes a range of 24°C.
Only with experience you will learn about your body and gear, try the variables and learn the weighting factor each has for you. Until then there may still come a few not so comfortable nights.
The good news: When you think you know how it works, your body gets older and you start again ;)