Remote canister stoves with a pre-heat mechanism are indeed game changers in terms of how gas stoves operate and how cold of a temperature you can operate the stove in.

With upright canister stoves, vapor is drawn off the top. The better cold weather gasses (propane and isobutane) vaporize at a faster rate. Your fuel blend changes over time, with decreasing performance as you near the end of the canister.

When you invert the canister, you're now drawing liquid off the bottom. Since you're not drawing vapor, the respective vaporization rates of the component fuels are simply not relevant. The liquid you draw off the bottom continues to be the same blend as what you started with. If you started off with a fuel blend with good cold weather performance characteristics, you'll finish with a fuel blend with good cold weather performance characteristics*. With a blend of 30% propane and 70% isobutane, a remote inverted canister gas stove will run fine at temperatures below 0F/-18C. Also, since you're doing liquid withdrawal, you're not going to have the same amount of evaporative cooling of the fuel. In other words, your inverted fuel canister won't get as cold as an upright canister -- further contributing to good cold weather performance.

Below 40F/5C, I generally recommend switching either to a remote inverted canister stove or a liquid fueled stove. Yes, you can run an upright canister stove at lower temperatures, but you're going to get a lot better performance out of a remote inverted canister or liquid fueled stove.

HJ

*In actual practice, some remote inverted canister stoves -- those that require the canister to be upright during startup -- will experience changes to the fuel blend over the life of the canister.