I have always used a Svea or MSR when the temperatures plunged, although I really like a Trangia in more moderate to warm conditions.

I am a fan of lightweight equipment, but the extra weight of a liquid fuel stove, relative to its potential utility in really cold conditions, makes for a no-brainer decision - carry the heavier stove.

Another benefit is that the gasoline/kerosene fuel makes a sure fire igniter if you go to a wood fire in tough conditions - use with extreme care!

Funny thing, with advancing age, I, too, am going out less in really cold conditions.