I can only describe traditional Camping Gaz cylinders (100% butane, isomer unknown) as being 'almost completely useless' in cold weather. Even with propane/isobutane in the mix the performance in cold weather is not as good as a decent liquid fuel stove,
One thing to bear in mind is that the proportions of gas in a canister aren't constant, so those curves only apply to new or pure butane canisters (pure propane isn't usable in a lightweight context).
If you are using a regular 70% n-butane, 30% propane liquid gas mix canister (Coleman etc), at 10°C, and reading the curves above, the gas coming out of a new canister is n-butane at 0.7 x 1.5* bar plus propane at 0.3 x 6.5* bar, which works out at a gas mix of 35% butane + 65% propane at 2* bar.
Since you are using the propane nearly twice as fast as the butane, the liquid gas mix changes, as does the mix and pressure of the gas going to the stove. As it gets warmer, the proportion of n-butane to propane increases, but not drastically so (0°=33/67, 30°=39/61).
* the graph uses gauge pressure (i.e. relative to atmospheric), so you've got to add one to get absolute pressure. The "butane" is also n-butane, not isobutane.
By the time the canister is less than 2/3 used, there's very little propane left, so the performance of the stove falls right off, enough not to run at all if it's down close to zero.
This affects all gas stoves that use an upright canister.
Solutions include warming the canister by body heat, a handwarmer, or warm water saved in a thermos, or, if there's enough gas to actually light the stove, pepping up performance by (carefully) redirecting heat from the burner to the canister with a close fitting windshield or a strip of copper or aluminium taped to the canister at one end and in the flame at the other.
The real answer is to use a remote canister stove that allows the use of an inverted canister (i.e. with a preheat loop), so you burn gas in the same proportions as in the liquid, and retain the propane content through the life of the canister. Suitable stoves include the MSR Windpro, Optimus Vega, Edelrid Opilio, Primus Express Spider, Alpkit Koro (and other versions of the Fire Maple FMS-118) etc.