The very traditional SVEA 123 and similar models are quite compact, having about the same profile as a canister stove like the Pocket Rocket. Due to the brass tank, they are heavier, but you have a compact unit with its own self contained fuel supply. You will need a pot support and windscreen. Carry additional fuel in a separate container if you wish.

I have never tried Esbit tablets in really cold weather; I am a bit skeptical about their value in that situation.