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.
Esbit in my experience has a relatively weak flame. For melting snow, I wouldn't recommend although for emergency use,
maybe it has some value.
The Svea is kinda heavy, but it does the job. You can get a mini pump for it which helps get it going in cold weather.
Seriously though, if you've got an Omnifuel, it doesn't get much better than that. You can run it in inverted canister mode for intermediate cold weather and with liquid fuel in seriously cold weather.
I don't know that there's a "magic bullet" out there of a compact, light stove for cold weather use. Maybe the Borde stove, but they're tough to find and have their drawbacks.
HJ