Hey Princess

That is actually the reason for no hats, because it stops heat from escaping, thus increases the chance of overheating.

It's really hard to know what to do in this weather...I feel the cold badly, so I overdress my baby according to DP. I think it's colder than it is and have about 3-4 blankets doubled over at night on him, one bonds wondersuit and also a heater running in our room. This does not appear to overheat him though. Then he co-sleeps after his first wake up of the night as he's usually very cold and I have him next to me with a doona over him up to his chest. We have two doonas on our bed, so I'm careful only to have one on him and he snuggles to me so that usually makes him warm enough.

Don't be hard on yourself at all, it's very hard to know. Having a winter baby is harder than a summer one for this reason.