Hair heat protection help

Hi ladies, need a bit of guidance from those wiser than me.

I have really fine curly hair (and not a huge amount of it either, thanks genes). Barely dry my hair with a hairdryer, but I want to do it this winter. Two winters ago I chopped half my hair off because it was just ruined.

Typically what I do is wash it once or twice a week, and then condition it, plus use a serum, then leave it to dry naturally. I also JUST condition about twice a week.

In winter I barely do it like that because it's cold to sit with wet hair so often (we don't have central heating at home). Last year I used a hot oil treatment twice a week, then washed and conditioned as normal but I didn't do extra conditioning.

So this year I want to keep my washing twice a week, conditioning four times a week BUT I want to blowdry my hair so I'm not sitting with wet hair almost every day of the week.

My question is, do I use the serum before I blowdry, or after, or not at all? Do I just dry my hair with a t-shirt and then apply the heat protector and that's it? How can I keep my hair as protected as possible in the harsh winter conditions if I'm blow-drying it?