Malaysia would not be Malaysia anymore if it had cold winter.
No coconut, palm oil or banana etc, totally different food. Nasi Lemak replaced with potatoes.
Infrastructure would need to be totally different. Nothing is built to handle sub zero degrees. Forget going to school or work on moto. I wonder how DBKL snow plowing would work if same mentality.

In cold places, if you do not plan ahead, you die. As simple as that. You need to have a warm house and a way to stay warm and fed during the long winter when nothing grows. You cannot just live day by day. Of course in modern societies you can still survive a winter beeing a retard, but that is just beacuse someone else has done the planning for you.

A lot of people in Sweden got electric heating. Was made popular in 1980's when the country had over invested in nuclear power and had too much spare electricity capacity. Now those people are trying to convert to other ways of heating though. Still I know quite a few who still use it. Converting to other heating modes is expensive also.

Is Singapore a rule or an exception?

Actually a lot have direct heating with electric radiators. Heat pumps is what they usually switch to to lower cost

At +19 C Scandinavians put on swimming trunks, bikinis and go to the beach. Kids swim, most adults probably think too cold. Typical summer temperature .