Thanks for the replies. Maybe I will just stick with a regular cycling helmet with a cover. Last year I was out in -45C weather and howling wind and my head never really got cold (thanks to this ) but I've always had a paranoia about falling and breaking my teeth, hence the jaw guard on previously linked helmet. Plus the tightness of the cycling helmet over that belaclava leaves pronounced ridges on my head and gives me a headache.

I guess the solution is to buy a cheapy XL helmet and possibly a helmet cover.

Thanks.